Climate Change Vulnerability and Potential Conservation Actions: Seabirds in the North-East Atlantic

8Steller’sEider (Polystictastelleri)60

9CommonEider(Somateriamollissima)62

10KingEider(Somateriaspectabilis)66

Potentialactionsinresponsetoclimatechange:DucksandPhalaropes(Anatidae andScolopacidae)68

GannetsandCormorants(SulidaeandPhalacrocoracidae) 73

1NorthernGannet(Morusbassanus)74

2EuropeanShag(Gulosusaristotelis)76

3GreatCormorant(Phalacrocoraxcarbo)78

Potentialactionsinresponsetoclimatechange:GannetsandCormorants (SulidaeandPhalacrocoracidae)80

Gulls(Laridae) 87

1EuropeanHerringGull(Larusargentatus)88

2Audouin’sGull(Larusaudouinii)90

3CaspianGull(Laruscachinnans)92

4LesserBlack-backedGull(Larusfuscus)94

5GlaucousGull(Larushyperboreus)96

6GreatBlack-backedGull(Larusmarinus)98

7IvoryGull(Pagophilaeburnea)100

8Black-leggedKittiwake(Rissatridactyla)102

9Sabine’sGull(Xemasabini)106

10Yellow-leggedGull(Larusmichahellis)108

Potentialactionsinresponsetoclimatechange:Gulls(Laridae)110

Loons/DiversandGrebes(GaviidaeandPodicipedidae) 127

1ArcticLoon(Gaviaarctica)128

2CommonLoon(Gaviaimmer)130

3Red-throatedLoon(Gaviastellata)132

4HornedGrebe(Podicepsauritus)134

5Red-neckedGrebe(Podicepsgrisegena)136

Potentialactionsinresponsetoclimatechange:Loons/DiversandGrebes (GaviidaeandPodicipedidae)138

PetrelsandShearwaters(HydrobatidaeandProcellariidae) 141

1Cory’sShearwater(Calonectrisborealis)142

2NorthernFulmar(Fulmarusglacialis)144

3Band-rumpedStorm-petrel(Hydrobatescastro)146

4Leach’sStorm-petrel(Hydrobatesleucorhous)148

5EuropeanStorm-petrel (Hydrobatespelagicus)150

6ManxShearwater(Puffinuspuffinus)152

Potentialactionsinresponsetoclimatechange:PetrelsandShearwaters (HydrobatidaeandProcellariidae)154

Skuas(Stercorariidae) 161

1GreatSkua(Catharactaskua)162

2Long-tailedJaeger(Stercorariuslongicaudus)164

3ArcticJaeger(Stercorariusparasiticus)166

Potentialactionsinresponsetoclimatechange:Skuas(Stercorariidae)168

Terns(Laridae) 177

1ArcticTern(Sternaparadisaea)178

2LittleTern(Sternulaalbifrons)180

3RoseateTern (Sternadougallii)182

4SandwichTern(Thalasseussandvicensis)184

5CaspianTern(Hydroprognecaspia)186

Potentialactionsinresponsetoclimatechange:Terns(Laridae)188

Appendices 195 Appendix1:Auks196

Appendix1:DucksandPhalaropes212 Appendix1:GannetsandCormorants225

Introduction

0.1Whatisthisdocument?

ThisdocumentispartofaseriesproducedbytheZoologicalSocietyofLondonand theUniversityofCambridge,whichaimsto(1)assessseabirds’vulnerabilityto climatechangeintheNorth-EastAtlantic,and(2)identifypotentialconservation actionsthatcouldreducethisvulnerability.Thisguidancecollatesinformationfrom thescientificliterature,non-governmentalorganisations’reports,conservation practitionerinputandonlinedatabasesintoasingledocument,andprovidesa referencemanualtoassistconservationplanning.Itisintendedtobeusedbyanyone whowishestoidentifyclimatechangethreatstoseabirds;tocomparethreats betweendifferentareasoftheNorth-EastAtlantic;tostartaquantitativeclimate changevulnerabilityassessmentforalocalpopulation;ortoreviewoptionsfor conservationactioninresponsetoclimatechange.

ThisdocumentsynthesisesavailableinformationforseabirdsintheNorth-East Atlantic.TheNorth-EastAtlanticcoverstheOSPARregionofEurope,fromthe BarentsseaandSvalbardintheNorth,tothecoastofPortugalintheSouth.Wealso includedspeciesandpopulationsbreedinginandaroundtheBalticsea;this adjustmentwasmadeinresponsetoknowndistributionsofsignificantfishstocks,as wellasinformationonareasknown tobeimportantbreedingand/or winteringgroundsforspecies otherwisecommoninWestern Europe.Wedidnotassessspecies orpopulationsinthe Mediterranean,aroundGreenland, aroundtheAzoresoraroundthe Canaries.

Aspartofplanninganddeveloping thisseriesofdocuments,we consultedandcollaboratedwitha varietyofconservation stakeholdersandpractitionersfrom acrossEurope,andhaveaddedtheir

Theareacoveredbythisreport(shadedinblue) basedontheOSPARregionofthenorthAtlantic.

knowledgeandexperiencetocomplementtheavailablepublishedinformation.This includescurrentlyunpublishedimpactsandfirst-handexperienceonthepracticality andeffectivenessofconservationactions.Wewouldliketothankeveryonewho contributedtothedevelopmentofthiswork.Thisdocumentispartofversion1.0, publishedinDecember2022,butassessmentsmaybeupdatedbasedonfeedback andnewlyavailableinformation.Tocheckforupdatestoourassessments,please visitourwebsiteat:www.ZSL.org/seabird-guidelines.

0.2Whatthisdocumentcontains

Thisdocumentcontainstwomajorsections.Thefirstassesseshowvulnerable seabirdsintheNorth-EastAtlanticaretoclimatechange,andthesecondassesses theconservationactionsavailableforeachidentifiedclimatechangerelatedthreat. Wecarriedoutanassessmentforallseabirdspeciesthathaveapermanentbreeding populationintheNorth-EastAtlantic.

A“seabird”isnotadistincttaxonomicgroup,butisdefinedbyanyspeciesofbird thatpredominantlyreliesonmarinehabitatforatleastpartofitsannualcycle.We identified48species,looselygroupedasauks,cormorants,gannets,grebes,gulls, loons/divers,seaducks,skuasandterns.Thereareseveraladditionalspeciesthat aremarginallymarine,orhaveatleastafewpopulationsthataremarine,butin mostcasesweexcludedsuchspeciesastheyarepredominantlyassociatedwith terrestrial,freshwaterorestuarinehabitats.WeusetheEnglishcommonnames usedasstandardbyBirdlife,thoughothersynonymsmaybemorefamiliartosome readers.Inparticular,weuse“loons”ratherthan“divers”andreferto“murres”rather than“guillemots”.ForfurtherdetailspleaseseetheBirdlifeTaxonomicChecklist (http://datazone.birdlife.org/species/taxonomy). Thefollowingisasummaryofeachsectionoftheguidance.Forfurtherinformation onhowwecompiledeachsection,pleaseseeourcorrespondingappendicesthat containfullreferencesandinformationonsourcesused.Forafullmethodology,see theaccompanying‘Methodology’folderinAppendix2.

Section1:Vulnerabilitytoclimatechange.Sectiononereviewsthevulnerability ofeachaukspeciestoclimatechange,usingtheframeworklaidoutbyFodenetal., 2017.Itsubdividesvulnerabilityintothreemaincategories:

•Section1.1:Exposure. Exposureisadescriptionofthenature,magnitude andrateofchangesinducedbyclimatechange.Weassessedexposureinfour ways:

◦Section1.1.1:Currentimpactsonseabirdsattributedtoclimatechange. Thisisanumberedlistoftheimpactsofclimatechangeoneachspeciesthat

hassofarbeenobservedintheNorth-EastAtlantic.Animpactisdefinedasa changeinbreedingsuccess,abundance,survival,condition,behaviouror geneticsthatcanbeatleastpartiallyattributedtoclimatechange.This includes:a)long-termtrendsinpopulationswhereclimatechangeisbelieved tobeacontributingdriver,b)impactsofextremeclimateeventswherethe frequency/severity/durationofsucheventsisknowntobelinkedtoclimate change,c)anobservedsignificantincreaseinexposuretoaknownthreat(e.g. predators,parasites)whereclimatechangeisbelievedtobeacontributing factor.Impactsmaybe:positive,whereclimatechangehasresultedina positivechangetoademographicparameter(e.g.breedingsuccessor abundance),negative,whereclimatechangehasresultedinanegativechange toademographicparameter(e.g.breedingsuccessorabundance),orneutral, whereclimatechangehasclearlyhadaneffectonapopulationbutitisunclear whethertheeffectispositiveornegative(e.g.changeinphenologywithno recordedchangeinbreedingsuccessorabundanceetc.).Thelocationofthese impactsismarkedontheaccompanyingmapbynumberedicons.Forafulllist ofsourcesseeAppendix1.1.1.

◦Section1.1.2Potentialchangesinbreedinghabitatsuitability. Wehere aimtopredicthowmuchofthespecies’currentbreedingrangewillbe significantlylesssuitablein2070-2100,baseduponchangestothemarineand terrestrialenvironment.Wealsoestimatewhatproportionislikelytoremain suitable,andwhetherpartsofspecies’currentrangeswillbecomemore suitable.Theunderlyingspeciesdistributionmodel(SDM)considerspredicted changesintemperature,precipitation,salinity,distancefromtheseaand marinechlorophyllconcentration,aswellasseveralspecies-specificvariables whicharedetailedintheappendices.Aftercomparingestimatedhabitat suitabilitybetween2020and2070-2100,wesplitthecoastalregionofNorthWestEuropeintooneofthefourfollowingcategories:1)Habitatiscurrently suitableforagivenspeciesbutwilllikelybecomesignificantlylesssointhe future(markedinredonthemap),2)Habitatiscurrentlysuitableandwilllikely remainstableinthefuture(markedorangeonthemap),3)Habitatiscurrently suitablebutwillbecomesignificantlymoresointhefuture(markedgreenon themap)and4)Habitatisnotcurrentlysuitableandwillnotbeinthefuture (notmarkedonthemap).Thereisconsiderableuncertaintyaroundthese estimates,andassuchtheyshouldbeunderstoodasanindicatorofriskrather thanafirmprediction.Notethatmapsareaggregatedandenlargedtomake smallislandsmorevisibleandarenotexactrepresentationsofspeciesranges.

◦Section1.1.3:Predictedchangesinkeypreyspecies. Foreachspecies wecompiledalistofkeymarinepreyspecies,aswellasexistingestimatesof howtheirrangeandabundancemaychangebetweennowand2100.We

identifiedareaswhereoneormorekeypreyspeciesarelikelytobecome significantlylesscommoninthefutureandhighlighttheseasareasofhigh risk.

◦Section1.1.4:ClimatechangeimpactsoutsideofEurope. Insomecases climatechangeisknowntoimpactpopulationsoutsideofourstudyarea. ThesedataprovidesupportingevidenceforimpactsinEurope,highlighting impactsthatmaybeofconcerntopopulationsinthefuture,evenifthose impactshavenotsofarbeenobservedintheNorth-EastAtlantic.Inselected cases,wesummarisethenatureoftheimpactsandthegeneralareainwhich theyoccur.FurtherdetailsandreferencesareprovidedinAppendix1.

•Section1.2:Sensitivity. Sensitivityisthedegreetowhichaspeciesislikely tobeaffected,eitheradverselyorbeneficiallybyclimatechange.Sensitivityis expectedtobeshapedbyspeciestraits(e.g.bodysize,homerangeareaor sociality)andisdeterminedlargelybyintrinsic,biologicalfeaturesthathave evolvedovertime.WeusedalistofcandidatetraitsbasedonFoden&Young (2016)andidentifiedwhich,ifany,eachspeciespossesses.

•Section1.3:Adaptivecapacity. Adaptivecapacityisthepotential,capability, orabilityofaspeciestoadjusttoclimatechange,tomoderatepotentialdamage, ortorespondtotheconsequences.Thismaybeeitherthroughchangesin behaviourorchangesinphysiology.Weusedalistofcandidatetraitsbasedon Foden&Young(2016)andidentifiedwhich,ifany,eachspeciespossesses.

Section2:Potentialconservationactions.

Inthissectionwelistpotentialconservationactionsinresponsetoclimatechange impactsandtheevidencebehindtheireffectiveness.Foreachimpactwehave compiledalistoflocalactionsthatmaypreventorlimitthedirectorindirectimpacts ofclimatechange.PotentialconservationactionswerecompiledfromConservation Evidence(Williamsetal.2013)aswellassupplementaryliteraturesearchesof publishedseabirdconservationstudiesuptoJuly2021,andfromdirectconsultation withpractitioners.

By“localaction”wemeanconservationactionsthatdirectlypreventorlimitan impact,andactonalocalpopulationscale.Whilebroaderscaleactiontackling climatechangeandecosystemscaleconservationareincrediblyvaluable,weintend thisresourcetobeusedasaguidetohelpconservationofpopulationsatalocal level.Seethe“makingevidence-baseddecisionsandhowtousethisguidance” sectionforfurtherinformation.

Wedonotincludeactionsthataimtoincreasetheresilienceofseabirdpopulations

toclimatechangebyreducingotherimpacts(e.g.legalprotectionofspecies,hunting bans,reducingpollution).Insomecaseswhereveryfewviabledirectactionsare available,orlikelytobeeffective,weincludesomediscussionofindirectactionsto supportpopulations.However,indirectactionsareoftenpartofcomplexcause-andeffectpathways,anditisverydifficulttoassesstheiroveralleffectivenesson conservingseabirdpopulations.

By“directimpact”wemeanthedirectphysicalimpactsofclimatechange,orrelated changesinthephysicalenvironment,onseabirds.Exampleswouldbeheatstress causedbyrisingtemperaturesorincreasedphysiologicalcostsofforagingdueto strongerwinds.By“indirectimpact”wemeanchangesinecologicalprocessesthat thenimpactseabirds.Exampleswouldbechangesinpreyrange,abundanceor composition,increaseinpredationduetorange-shifts,orchangesindisease prevalence.

Wedonotincludeactionsinresponsetohumanactivities,evenifthedistributionor intensityofthesemightbeinfluencedbyclimatechange.Forexample,renewable energyinfrastructureislikelytochangeinresponsetoclimatechange,andislikely toincreaseexponentiallyinfuturedecadestotackletheclimatecrisis.However,as thisisahuman-mediatedimpact,itisnotincludedinthisguidance.

Forthissectionwegroupbyclimatechangeimpactratherthanspecies.Forexample, ifmultiplespeciesarelikelytosufferpreyshortagesinthebreedingseason,we summarisethepossibleactionsinresponseforallspeciesinthegroupatonce.If actionsandevidencearespecifictooneorafewspecies,thisisdiscussedinthe actionsummaryandfootnotes.

Foreachactionweassessedtheavailableevidenceaboutitseffectivenessandthe relativestrength,relevanceandtransparencyofthesupportingevidence(onascale from1to5).Thefollowingpointsgiveanoutlineofthecriteriausedtoassesseach score;forafullmethodologyseeAppendix2.Foreachaction,wealsoprovidealist ofreferencesandsourcesweusedinAppendix2.

•Effectiveness: Foreachactionweassessedhoweffectiveitwaswhencarried outonseabirds.Eachconservationactionisratedbasedontheevidenceforits effectiveness,rangingfrom“likelytobebeneficial”to“likelytobeharmful”. EffectivenesscategoriesaretakenfromConservationEvidence(Williamsetal. 2021),andthuspertaintoallbirdsunlessnotedotherwise.Forafullmethodology seeAppendix2.Studiesdocumentingactions’effectivenessspecificallyon seabirdswereusedastheprimaryevidencebase,butifasuggestedactionhas notbeentrialledonseabirdswealsoconsultedavailableevidencebasedon conservationstudiestargetingotherbirdspecies.Wealsoincludedinformation frompractitioners(ifavailable)regardinganaction’seffectivenessorpracticality

forkeypopulationsinEurope.

•Strength: Thisreferstoseveralcharacteristicsoftheunderlyingevidencebase regardingtherelativerobustnessandcoverageoftheevidence.Inparticular,itis basedonhowmanystudieshaveexploredagivenconservationaction,didthey testitonalargenumberofindividualsorhavealargenumberofreplicates,has itbeentestedinvariouspartsofaspecies’range,anddidtheauthorshaveaclear andsensiblemetricforsuccessandwasitmeasuredrobustly.

•Relevance: Thisreferstohowmuchoftheunderlyingevidencebaseis composedofevidencespecificallyregardingthespeciesgroupinquestion (e.g.auks).Ifanactionisratedasbeneficial,thentherelevancescorereferstohow confidentpractitionerscanbethatagivenconservationactionisbeneficial specificallyforthefocalspeciesgroup.

•Transparency:Thisreferstohowmuchoftheunderlyingevidencebaseis composedofevidencethathasclearmethodology,readilyavailableanddetailed data,andaclear,evidence-basedrationale,allofwhichhaspreferablybeenpeerreviewed. Appendices

Asanevidence-basedguidancedocument,beingclearaboutwheretheinformation underlyingourassessmenthascomefromiskey.Therefore,foreachofthesections inthemaintextthereisacorrespondingappendixsectioncontainingreferences, additionaldetailornotesonmethodologyforthosewhowishtoexaminetheprimary sourcesorfindadditionalreading.Appendix1containsadditionalinformationfor Section1oftheguidance,andAppendix2containsadditionalinformationforSection 2.Subheadingsintheappendixmatchthoseinthemaintext.Forexample,ifyou wouldliketofindthesourcesweusedtocreateSection1.1.1(Currentimpacts attributedtoclimatechange),thenpleaseconsultAppendix1.1.1.

0.3Whatthisdocumentdoesnotcontain

Arelativeassessmentofriskoreffectiveness.Differentpopulationsfacedifferent combinationsofrisksandtodifferentdegreesofseverity.Forthisassessmentitwas notpossibletoassessorrankthegreatestthreatstoeachpopulation.Instead,we listallidentifiedfactorsthatcontributetovulnerabilityandtheevidencebehind them.Practitionerscanhoweverusethisguideasastartingpointtoassessthreats posedbyclimatechangetotheirlocalpopulation.

Recommendationsforspecificcoursesofaction.Thisguidanceisintendedforuse

bypractitionersasareferenceguidetohighlightthreatsandpotentialconservation actionsforagivenspecies.Whatactionismostappropriateinagivenscenariois dependentonmanydifferentfactors,includingecological,financial,politicaland socialconcerns.Thisguidanceshouldbeconsideredinadditiontotheexperienceand judgementofthosewhoworkinthefield.

0.4Makingevidence-baseddecisionsandhowtousethisguidance

Thisguidanceisaresourceforamuchwiderframework,namelyassessingthreats tobiodiversityandcarryingoutevidence-basedconservationaction.Thereare severalpublisheddecision-makingframeworksforconservation,andwewillprovide anexampleherebasedontheevidence-to-decusuibtool(https:// evidence2decisiontool.com/),whichidentifiesthreemajorstepstomakingdecisions. Here,weprovideabriefsummaryofthesestepsandthendetailwhereandhowthis guidanceisintendedtofacilitatethisprocess.

1)Definethedecisioncontext. Whatisbeingtargeted,aspecificsite,aspecies, apopulation,orother?Isthereathreatthatneedstobeaddressed?Ifthereare multiplethreats,whichshouldbeaddressedfirst?Whichthreatisthemosturgent, shoulditbeaddressedfirstasapriority?Howmuchimpactcouldthisthreathave? Whataretherelevantecological,physical,socioeconomicandculturalfactorsthat maybebeneficialorabarrierforconservation?Whatarethegoalsofthe conservationeffort(thismayincludeshort-termandlong-termgoalssuchas: successfullymovingnests,decreasingnumberofnestsdestroyed,increasing fledglingsuccessrate,increasingpopulationsizeoveradecade)?

2)Gatherevidence. Ifactionisneededinresponsetoidentifiedthreats,what arethepotentialactions?Whatistheevidencebehindtheseactions;whichare knowntobeeffective?Isthisactionlikelytobeeffectivewhenappliedtothespecific situationathand?Isanactionfeasibletocarryoutatthescalerequired?Whatare thefinancialandphysicalresourcesneeded?Whataretherisks,costsandbenefits ofeachaction?Isitpossibletherewillbeunintendedconsequences?Istheaction acceptabletostakeholders(e.g.willtheactionnegativelyimpactanother conservationtarget)?

3)Makeanevidence-baseddecision Whichthreatsneedtobeaddressed? Whichactionsshouldbecarriedout?Whatisthejustificationforthesedecisions? Aftercarryingoutstages2and3,itmightbethattheprimarythreatisextremely difficulttoaddress,soisthereanotherwaytosupportapopulationbyaddressing another,secondarythreat?Shouldtheactioninsteadfocusonsupportingand protectingthepopulationinanotherway?Howwillyoudocumentandreportthe conservationproject?Howwillyoumonitorandevaluatethesuccessoftheaction?

Thisguidancedocumentprovideskeyinformationforsteps1and2oftheabove framework. 1) itaimstohelppractitionersidentifycurrentandfuturethreatsto seabirdspeciesfromclimatechange,andwherethesearelikelytobemostpressing. Thisguidancefocusesonspecies-levelcontextandidentifiesecologicalandphysical factors(throughsensitivityandadaptivecapacity),thataremajorbarriersand opportunitiesforspeciestoadapt. 2) Thisguidancelistspotentialactionsinresponse toidentifiedclimatechangeimpacts.Practitionerscanreviewthesepotentialactions, andassessmentsoftheireffectiveness.Whileit’snotpossibletoprovidesite-specific context,wehavealsoincludedsomeinformationonacceptabilityandfeasibility basedonpractitionerexperienceandfeedback.

Whencombinedwithpractitionerexperienceandjudgement,thisguidanceshould assistdecisionsregardinghowto(a)prioritisespeciesandareasforconservation, and(b)makeanevidence-baseddecisiononifandhowactiveinterventionshould becarriedout.

0.5References

Foden,W.B.,etal.“Climatechangevulnerabilityassessmentofspecies.” WIREsClimChange10.1(2019):e551.

Williams,D.R.,etal.“Birdconservation:globalevidencefortheeffectsof interventions”.Vol.2.PelagicPublishing(2013).

Williams,D.R.,etal.“BirdConservation.”Pages137-281in:W.J. Sutherlandetal.(Eds.)WhatWorksinConservation2021.OpenBook Publishers,Cambridge,UK(2021).

0.6License

Youareencouragedtouse,andre-use,informationsubjecttocertainconditions.If youchoosetouseinformationfromthisreport,pleasegiveappropriatecreditby providingacitationtothisreport,alinktothepublishedreport,andindicateif changesweremade.AllphotosarecopyrightSeppoHäkkinenandSilviuPetrovan, unlessnoted.

0.7Preferredcitation

Häkkinen,H.,Petrovan,S.,Taylor,N.G.,Sutherland,W.J.,Pettorelli,N.“Climate ChangeVulnerabilityandPotentialConservationActions:SeabirdsintheNorth-East Atlantic.”ZSLInstituteofZoologyandUniversityofCambridge(2022):1-274. Availableat:www.ZSL.org/seabird-guidelines

0.8Contributors

Wewishtothankthefollowingpeoplefortheirinputonthisproject,withouttheir knowledge,experienceandfeedbackthisprojectwouldnothavebeenpossible:Jón Aldará;HanyAlonso;OreaAnderson;TychoAnker-Nilssen;HelderAraújo;José ManuelArcos;ChristopheAulert;BryonyBaker;ElmarBallstaedt;Robvan Bemmelen;DanielBengtsson;RichardBerridge;JulieBlack;DaisyBurnell;Bernard Cadiou;KeesCamphuysen;LetiziaCampioni;RodrigoMartínezCatalán;BethClark; NinaDehnhard;MariaDias;LeonieEnners;MatsEriksson;JaviFranco;Morten Frederiksen;BobFurness;MariaGavrilo;RosGreen;GunnarThorHallgrimsson; SjúrðurHammer;ErpurSnærHansen;SveinnAreHansen;MarttiHario;Stephen Hurling;LinnetJessell;MarkJessop;RebeccaJones;BirgitKleinschmidt;UršaKoce; YannKolbeinsson;JorisLaborie;AdrienLambrechts;MeelisLeivits;Raphaël Leprince;UlrikLötberg;KlaudynaManiszewska;MikeMeadows;SzabolcsNagy; SteffenOppel;AnaPayo-Payo;KjeldTommyPedersen;DanielPiec;JaimeRamos; FredericRobin;AðalsteinnÖrnSnæþórsson;IbenHoveSørensen;AntraStipniece; SophieThomas;DanniThompson;AntonioVulcano;EricWalter;IlkaWin;Ramunas Žydelis

0.9Funding

Wewouldliketothankourfundersfortheirsupportduringthisproject.Thisworkis fundedbyStichtingAveFenixEuropa.NPisfundedbyResearchEngland.SPandWJS arefundedbyArcadia,TheDavidandClaudiaHardingFoundationandMAVA.

1Razorbill (Alcatorda)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (80%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(18%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts

climatechange:

NegativeImpact: Extreme stormsduringtherazorbill breedingseasonhaveledtowide-spreadnestdestruction,nestingfailureanda netreductioninannualpopulationproduction.

NegativeImpact: Asseatemperatureshaveincreasedovertime,razorbill productivityhasdecreased,mostlikelyduetochangesinpreyavailability.

NeutralImpact: Keypreyspecieshaveshiftedtheirlife-cycle,likelyin responsetoclimatechange,butrazorbillshavenotadjustedinresponse.There isconcernthiscouldresultintrophicmismatch,butnooveralleffecton breedingsuccesshassofarbeenobserved.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheBaltic,theIrish SeaandtheEnglishChannel.

1.2Sensitivity

•Razorbillsprefertonestinexposedplaces,whichmakesnestsparticularly vulnerabletostorms.Anyincreaseinthefrequencyorintensityofstormsduring thebreedingseasonislikelytohavesevereconsequencesonrazorbillbreeding success.

•Razorbillsurvivalinmanyareascorrelateswithseasurfacetemperature, likelyduetochangesinpreyabundance.Projectedtemperatureincreasesare thereforelikelytodecreaserazorbillsurvivalduringthenon-breedingseason.

•Razorbillsarepronetomass-mortalityevents(“wrecks”),bothacrossEurope andinNorthAmerica.Theexactcausebehindthemisnotcertain,butlikely relatedtofoodavailabilityandwinterstorms.Thismakesdrasticpopulation reductionsmorelikely,aswelllongrecoveryperiods.

•Manyrazorbillpopulationsareheavilyreliantonafewpreyspecies, especiallyduringthebreedingperiod.Anychangeinpreyavailability, particularlysandeels,islikelytohaveconsequencesforrazorbillpopulations.

•Razorbillsarevulnerabletomammalpredation,andthespreadofintroduced mammals(favouredbyclimatechange)couldthreatenmorenorthern populationsthanpreviously.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Razorbillsarepelagicandareeasilycapableofreachingnewpotentialcolony sites.InNorthAmericathereissomeevidencetheywillcolonisenewareasto matchkeypreyspeciesranges.However,thereisnoobservedexampleofthis occurringinEurope.

2LittleAuk (Allealle)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (94%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(6%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: Warmer temperaturescorrelatewith longerforagingtripsandlowerlittleaukproductivity,mostlikelydueto decreasedpreyavailability.

NeutralImpact: Littleauksarebreedingearlierincorrelationwithwarmer temperatures,sofarnonegativeconsequencehasbeenobserved.

NeutralImpact: Extremestormsduringthenon-breedingseasonhaveled tomassmortalityoflittleauks(‘wrecks’).

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•Lossofseaiceandavailabilityofnewpreyitemsduetoclimatechangehas ledtoincreasedlittleaukbreedingsuccessinGreenland.

•

1.2Sensitivity

•Littleauksexpendagreatdealofenergyinflight,andtheirchicksalsohave veryhighenergydemands.Thismeansthatauksmustfocusonhigh-energy preyandaresensitivetoevensmallchangesinhigh-energypreyavailability.

•Aukcoloniesthatnestnearwarmerseastypicallyhavelongerandless successfulforagingtripsfornestingauks,whichultimatelylowerschickgrowth andsurvival.Populationsthatthereforenestinareaswithprojectedincreases inseatemperaturewouldlikelybenegativelyimpactedbyclimatechange.

•LittleauksonSvalbardmayrelyonenvironmentalsignalstotimebreeding events,inparticularthetimingofsnowmelt.Thistheoryisnotconfirmed,but issupportedbyrecentobservedchangesinphenology.Ifthereisastrong relianceonsuchenvironmentalcues,itmayleadtotrophicmismatchwithprey speciesinthefuture.

•Littleauksaredependentonafewspeciesofcopepodsthroughouttheyear.

Anychangesinavailabilityorrangeofthesespeciesislikelytohaveasignificant impactonlittleauks.

•Littleaukscongregateinlargenumbersinarelativelysmallareainthe non-breedingseasonintheAtlantic.Anynegativeimpactinthisareaislikelyto havesevereconsequencesforlittleaukpopulations.

•Littleauksareknowntobesensitivetoclimatechange,andhavesuffered regionalextinctions.Theyhavepreviouslysufferedrangecontractionsandlocal extinctionsinthe19th-20thCenturymostlikelybecauseofglobalwarming (thoughhistoricalchangeswerenotprimarilyanthropogenic).Asaresultithas lostmuchofitspreviousrangeinIcelandandGreenland.

•Littleaukpopulationsarelarge,butmanyarepoorlymonitoredandexposed tomultiplepotentialpressures.Impactsmaybedifficulttoidentifyand conservationislikelytobedifficulttocarryout.

1.3Adaptivecapacity

•LittleauksinSvalbardandGreenlandhaveplasticforagingbehaviourthat hashelpedthemcompensateforlocalchangesinpreyavailabilityandseaice. Howeverthisplasticitylikelyhasalimitandprojectionssuggesttheycanonly compensatetoacertainextent.

•Littleauksarethoughttoshowstrongfidelitytobreedingsites.Thismay reducetheabilityoflittleaukstoadapttochangesinlocalconditions,asthey areunlikelytochangebreedingsitesinresponsetochange.

3BlackGuillemot (Cepphusgrylle)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (76%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(24%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Heavy rainfalleventsandhighwater levelhasledtofloodingofnestsandlowerhatchingsuccessintheBaltic.Such floodingeventsarebecomingmorecommon,andarelikelytofurtherincrease. Debrisleftbystormsandfloodingcanalsomakelargeareasofshorelineless suitableforbreeding.

NegativeImpact: RangeexpansionofAmericanmink,partlyassistedby climatechange,hasledtoincreasedratesofpredationatguillemotcolonies.

NeutralImpact: Guillemotshaveshiftedtheirlayingdate,mostlikelylinked toanincreaseinseasurfacetemperatureandpreyavailability.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSeaandthe south-westcoastofSweden.

1.2Sensitivity

•Blackguillemotsareparticularlyvulnerabletopredationfromminkandrats, dueinparttotheirnestingonthegroundinexposedareas.Rangeexpansion ofmammalianpredatorsduetoclimatechange(whichisalreadyoccurringin Scandinavia)mayhavelargeimpactsonguillemotpopulations.

•Blackguillemotsoftennestinexposedareasclosetowaterlevel,whichmake themvulnerabletofloodingeitherfromsea-levelrise,extremeprecipitationor tidalsurges.Ifclimatechangeresultsinahigherfrequencyofanyofthese eventsduringthesummer,itcouldseverelyimpactblackguillemotbreeding populations.

•BlackguillemotsinEuropearedeclining,thoughwithhighlyvariableseverity. Therearevariousunderlyingcausesincludingmarinepollution,predationby invasivespecies,by-catch,disruptionbywindfarmsandhunting.Anyadditional pressurefromclimatechangeislikelytoacceleratethesedeclines.

1.3Adaptivecapacity

•Blackguillemotscanshifttheirphenologyinresponsetochangesin environmentalconditions.Theymaythereforebeabletoadjusttochangesin conditionsandpreyavailabilityandthereforemitigateimpactsofclimate change.

•Inrecentdecadesblackguillemotshaveestablishedseveralcoloniesinnew areasaroundtheIrishSeaandNorthAmerica,whichsuggeststheymaybe capableofrangeshiftsinresponsetoclimatechange.

4AtlanticPuffin (Fraterculaarctica)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (68%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(31%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Changes inpuffins’preyavailability duringbreedingseasonhasledtodecreasedbreedingsuccess.

NegativeImpact: Changesinpuffins’preyavailabilityduringnon-breeding seasonhasledtoincreasedmortalityandpopulationdeclines.

NegativeImpact: Changesinvegetationhasledtofewersuitablepuffin nest-sites.

NegativeImpact: Extremestormsduringthenon-breedingseasonhaveled tomass-mortalityofpuffins(‘wrecks’).

NeutralImpact: Puffinshavechangedtheirwinteringrange.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSeaandthe EnglishChannel.

1.1.4ClimatechangeimpactsoutsideofEurope

•SomecoloniesinNorthAmericahavechangedtheirlayingphenology, presumablyinresponsetotemperatureand/orpreyavailability.

1.2Sensitivity

•Puffinsarepronetopopulationcrashes,typicallyeitherfromlackofprey duringthebreedingseasonortheeffectsofwinterstorms.Thismakesdrastic populationsreductionsmorelikely,aswellaslongrecoveryperiods.

•Adultpuffinsurvivalcandropsharplywhenthereisanincreaseinthe frequency,durationandintensityofwinterstorms,mostlikelyduetoincreased foragingdifficulty.Note:thereisconflictingevidenceregardingtheeffectof stormsonpuffins.However,puffinsinareasmostpronetoextremeweatherare morelikelytobeseverelyaffected.

•PuffincolonysuccessacrossEuropeiscorrelatedtocopepodabundance,as theysupportmanyfishpopulations.Inrecentdecadesmanyareasinthesouth ofthenorth-eastAtlantichavebecomelesssuitableforcopepodsandthistrend islikelytocontinueinthefuture.Adecreaseorrangeshiftincopepodswilllikely havesevereimpactsonseabirdcoloniesinthenorth-eastAtlantic.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

•PuffinsaredecliningrapidlyinmanypartsofEurope,whichhasmostmajor populationsglobally.Anyadditionalpressurefromclimatechangeislikelyto acceleratethesedeclines.

1.3Adaptivecapacity

•Puffinstravellongdistancesandcouldtheoreticallyreachareassuitablefor newcolonies.However,whiletherehavebeenexamplesofpuffinscolonising newareas(withorwithouthumanassistance),ingeneraltheyhavehighsite fidelityandrarelycolonisenewareas.

•RecentobservationsinIcelandreportthatpuffinshavestartedtoswapprey speciesatsomecolonies,especiallywheremajorpreyspecieshavedeclined. Theextentofthisswitchandtheconsequencesarecurrentlyunknown.

•ColoniesofpuffinsonFarneIslandsandonIsleofMayarebreedinglater, butnotincorrelationtochangesinseatemperature.Thismaybeduetoother environmentalchangesinbreedingornon-breedingareas.Whilethisshiftmay beadaptive,itmayalsoresultintrophicmismatchifbreedingcuesdon’tmatch preyavailability.

5CommonMurre (Uriaaalge)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (66%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(31%).

Currentbreedingareathatis likelytobecomemoresuitable (3%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Highwindeventsinthenonbreedingseasonhaveledtomassmortalityofmurresinrecentyears.

NegativeImpact: Extremestormsduringthenon-breedingseasonhaveled tomassmortalityofmurres(‘wrecks’).

NegativeImpact: Morefrequentextremestormsduringmurres’breeding seasonhasincreasedforagingdifficultyandreducedfoodfedtochicks.

NegativeImpact: Extremestormsduringmurres’breedingseasonhaveled towide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.

NegativeImpact: Changesinmurres’preyavailabilityduringthebreeding seasonhasledtodecreasedbreedingsuccess.

NeutralImpact: Murresaremorelikelytoskipbreedinginwarmerweather, andthisbehaviourisbecomingmorefrequent.Whilethisisacauseforconcern, itisunclearwhateffectthiswillhaveonthepopulationinthelong-term.

NegativeImpact: Heatwaveshaveresultedinsignificantmurrechick mortality.Thefrequencyandseverityofheatwavesislikelytoincrease.

NeutralImpact: Commonmurreshavechangedtheirphenology, potentiallyinresponsetoclimatechangebutthemechanismisunclear.

PositiveImpact: Ashifttowardswarmer,drierandcalmerconditionshas correlatedwithhigherpopulationabundance.Mechanismunknown,butlikely mediatedthroughpreyavailabilityandlowerenergeticcosts.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheBaltic,theIrish SeaandtheEnglishChannel.

1.2Sensitivity

•Murresarepronetosporadicmass-mortalityevents(“wrecks”),bothacross EuropeandinNorthAmerica.Thelikelycausevariesbetweenwrecks,ranging fromsummerheatwaves,toprolongedextremewindeventsinwinter.Changes inextremeweatherarelikelytohavesignificanteffectsonmurremortality.

•MurresintheBalticaredependentonspratasafoodsourceandstudies suggesttheyhavelimitedabilitytoswitchtootherpreyitems.Declinesinsprat duetoclimatechangewouldlikelyhaveasevereimpactonmurres.

•MurrecolonysuccessacrossEuropeseemstobetiedtocopepodabundance, astheysupportmanyfishspecies.Inrecentdecadesmanyareasinthesouth ofthenorth-eastAtlantichavebecomelesssuitableforcopepodsandthistrend islikelytocontinueinthefuture.Adecreaseorrangeshiftincopepodswilllikely havesevereimpactsonseabirdcoloniesinthenorth-eastAtlantic.

•Formultiplepopulations,thereisastrongcorrelationbetweenbreeding successandseatemperatureincommonmurres;populationsarenegatively affectedbywarmertemperaturesmostlikelyduetochangesinmarine ecosystemsandpreyavailability.Projectedwarmingisthereforelikelyto negativelyimpactmanymurrepopulations.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

•WhilemostpopulationsinEuropearestable,somearedecliningrapidly (notablyinIceland).Anyadditionalpressurefromclimatechangeislikelyto acceleratethesedeclines.

1.3Adaptivecapacity

•Thereisevidencemurrescanchangetheirphenologyinresponseto temperaturechanges.Somepopulationshaveshiftedtheirlayingdatein correlationwithtemperaturechanges,othershavenot.Otherpopulationshave changedtheirarrivaldateaftermigration,butnottheirlayingdate.

•Thereappearstobeaweakgeneticstructureacrosscolonies,whichcould bearesultofhighdispersalbetweencolonies.Thismayincreaseresilienceand aidpopulationrecoveryfollowingwrecks.

•IncontrasttomurresintheBaltic(seeSensitivitysection),studieson populationsintheNorthSeaandeasternCanadahavefoundthatmurrescan switchpreyandspendmoretimeatseatocompensateforchangesinprey availability.

6Thick-billedMurre (Urialomvia)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (87%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(13%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Changes inthick-billedmurres’prey availabilityduringthenon-breedingseasonhasledtoincreasedmortality.

NegativeImpact: Changesinthick-billedmurres’preyavailabilityduring thebreedingseasonhasledtodecreasedbreedingsuccess.

NeutralImpact: Changesinthick-billedmurres’preyavailabilityduringthe breedingseasonhasledtoincreasedmortality.

NeutralImpact: Thick-billedmurrepopulationsaretypicallysmallerand declineinareaswithincreasingseatemperatures.Mechanismunclear.

NeutralImpact: Extremestormsduringthenon-breedingseasonhaveled tomassmortalityofmurres(‘wrecks’).

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•Thick-billedmurresareknowntobeimpactedbyclimatechangeoutsideof Europe.Impactsincludeincreasedpredationbypolarbears,increased parasitismbymosquitoes(leadingtobreedingfailure),andincreasedmortality causedbyalgalblooms.

•ChangesinthemarineecosysteminthecanadianhighArctic,drivenby climatechange,hasresultedinhigherconcentrationsofmercury bioaccumulatedinthick-billedmurres.Nolong-termimpactonpopulation healthhasbeenobservedsofar.

1.2Sensitivity

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Whileawide-roamingpelagicspecies,thick-billedmurreshaveveryhighsite fidelity.Moreover,juveniledispersalisalsoverylow.Itisunlikelythatmurres willestablishnewcoloniesinresponsetoclimatechange.

Potentialactionsinresponse toclimatechange:Auks (Alcidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increaseinmammalpredation

Summary:

Invasivemammalsareamajorthreattomanyseabirdpopulations,andassuch thereisawell-establishedliteratureonmammalexclusion,managementand eradicationdetailingeffectivemethodsandcasestudies.However,therearemore limitedoptionswhenthemammalianpredatorinquestionisitselfaconservation target,orisnoteasilymanaged.Nevertheless,formanysituationsthereare several,well-researched,actionsavailablethatcanbenefitseabirdpopulations effectively.

Intervention EvidenceofEffectiveness

Manage/ eradicate mammalian predators

Therearenumerousexamplesofbenefitsto seabirds,includingauks,followingmammal eradication,thoughthisdependsonthe effectivenessofthemethodsusedandthe speciesinquestion.Controlofrodentsand mustelidsareparticularlywellstudied.

Hasbeensuccessfullytrialledinnumerous ground-nestingseabirdspecies.However,we foundnostudiesthatlookateffectivenessfor anyaukspecies.

R S T

Reduce predationby translocating predators

Fewtrialsonseabirds,andonlyoneonauks (Synthliboramphus hypoleucus).Existing evidencesuggeststhisactioncanbe beneficialandreduceegg/chickpredation, andcouldbeapossibleactionifotherforms ofpredatormanagementarenotviable.

Repel predators with acoustic, chemicalor visual deterrents

Use supplementa ryfeedingto reduce predation

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

NA NA NA

Veryfewtrialsonseabirds,andnoneonauks. Nostudieshaveshownthisactioniseffective.

1 4 3 Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Manage/eradicatemammalianpredators

Relevance(R): 6studiesintheevidencebasefocusonauks,40onotherseabirds and3onotherbirds. Strength(S): Theevidencebasewascomprisedof52 studies.Ofthese44wereconsideredtohaveagoodsamplesize,and34hada clearmetricforeffectiveness. Transparency(T): 52studiesincludedwere publishedandpeer-reviewed,ofwhich5wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,24had apublishedmethodology,and28justifiedtheirrationale.

Physicallyprotectnestswithbarriersorenclosures

Relevance(R): 0studiesintheevidencebasefocusonauks,12onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof18 studies.Ofthese16wereconsideredtohaveagoodsamplesize,and12hada

clearmetricforeffectiveness. Transparency(T): 17studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,11hadapublishedmethodology,and12justifiedtheir rationale.

Reducepredationbytranslocatingpredators

Relevance(R): 1studyintheevidencebasefocussesonauks,1onotherseabirds and2onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and3hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and3justifiedtheirrationale.

Usesupplementaryfeedingtoreducepredation

Relevance(R): 0studiesintheevidencebasefocusonauks,1onotherseabirds and3onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and4hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and4justifiedtheirrationale.

2Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)increasesforagingdifficultyand/ormortality

Summary:

Invasivemammalsareamajorthreattomanyseabirdpopulations,andassuch thereisawell-establishedliteratureonmammalexclusion,managementand eradicationdetailingeffectivemethodsandcasestudies.However,therearemore limitedoptionswhenthemammalianpredatorinquestionisitselfaconservation target,orisnoteasilymanaged.Nevertheless,formanysituationsthereare several,well-researched,actionsavailablethatcanbenefitseabirdpopulations effectively.

Provide supplementary foodduringthe breeding season

Ifstormsaffectforagingduringthebreeding season,itmaybepossibletosupport populationswithadditionalfood.Alternatively itmaycounteractthepoorconditionof adultsafteraharshwinter.Trialledonmany seabirdspecies.Limitedevidencefor effectivenessinauks,andallknownstudies areon F.arctica.Typicallyverylabour intensiveanddifficultgiventheremoteand inaccessiblebreedingcoloniesofauks.Likely onlyplausibleforsmallpopulations.

Provide supplementary foodduringthe non-breeding season

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.Itislikelytobe verydifficultorevenimpossible,especially forpelagicspecies.

NA NA NA

Rehabilitate sickorinjured birds

Forothergroupsoflong-lived,largebirds, rehabilitationhasbeenshowntobeeffective (particularlyinraptors).However,examples inseabirdsarescarceandtheoverall effectivenessformostspeciesisunknown. Thefewexamplesthatexistforseabirds showmixedsuccessrates,butthereisat leastoneexampleofsuccessfulmasstreatmentfollowingstrandinginterns.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Providesupplementaryfoodduringthebreedingseason

Relevance(R): 5studiesintheevidencebasefocusonauks,11onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Rehabilitatesickorinjuredbirds

Relevance(R): 0studiesintheevidencebasefocusonauks,3onotherseabirds and4onotherbirds. Strength(S): Theevidencebasewascomprisedof7studies. Ofthese4wereconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T):7studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,5hadapublishedmethodology,and5justifiedtheirrationale.

3Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)causesnestdestruction

Summary:

Whilethereareseverallocalactionsthatmaypreventormitigatelocalnest destruction,theyhavenotbeentrialledwidelyandwide-spreadevidencetosupport theiruseiscurrentlylacking.Ifchangesinextremeweatherthreatenstheviability ofapopulation,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention EvidenceofEffectiveness

Alterhabitat toencourage birdstoleave anarea

Fewtrialsonseabirdsandnoneonauks. Severaltrialsofthisactionhavebeen successfulandencouragedternstoshift breedingsites.However,thisactionislikely moreviableforspecieswithlowersitefidelity andareaswithotheravailablebreedinghabitat nearby.

R S T

2 2 3

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Limited evidenceinauks,thoughcaptive F.arctica and F.cirrhata havebeensuccessfullyhand-reared.

Whilelikelytopreventfloodingthereis

Severalactionshavebeentrialledacrossauk (andotherseabird)speciestoencourage colonisation,withvariablesuccess,including theuseofdecoys,acousticcues,smellsand improvedhabitat.Themostnotablesuccess hasbeentousedecoystoencourage F.arctica tocolonisenewareas,otheractionshavehad variablesuccessdependingoncontextand species.

NA NA NA

3 5 3

1 3 5 Provide artificial nestingsites

Repair/support neststosupport breeding

Translocatethe populationtoa moresuitable breedingarea

Verylimitedevidenceforeffectiveness,but atleastonecasestudyhasusedthisaction toincrease U.aalge breedingsuccess.

Knowntobebeneficialinotherseabird groups,butevidenceforauksislimited.At leastonesuccessfultranslocationof F. arctica hasbeencarriedout,butwhetherit isgenerallyadvisableisuncertain.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 0studiesintheevidencebasefocusonauks,2onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof2studies. Ofthese2wereconsideredtohaveagoodsamplesize,and0hadaclearmetricfor effectiveness. Transparency(T): 2studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and1justifiedtheirrationale.

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 6studiesintheevidencebasefocusonauks,34onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T): 26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 1studyintheevidencebasefocussesonauks,37onother seabirdsand6onotherbirds. Strength(S): Theevidencebasewascomprisedof 44studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(flooding)

Relevance(R): 0studiesintheevidencebasefocusonauks,0onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and2hadaclearmetricfor effectiveness. Transparency(T): 3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,3hadapublishedmethodology,and3justifiedtheirrationale.

Provideartificialnestingsites

Relevance(R): 4studiesintheevidencebasefocusonauks,48onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof54 studies.Ofthese50wereconsideredtohaveagoodsamplesize,and33hada clearmetricforeffectiveness. Transparency(T): 53studiesincludedwere publishedandpeer-reviewed,ofwhich2wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,33had apublishedmethodology,and27justifiedtheirrationale.

Repair/supportneststosupportbreeding

Relevance(R): 1studyintheevidencebasefocussesonauks,1onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T): 3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and3justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 1studyintheevidencebasefocussesonauks,14onother seabirdsand0onotherbirds. Strength(S): Theevidencebasewascomprisedof 15studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hada clearmetricforeffectiveness. Transparency(T): 14studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,11had apublishedmethodology,and9justifiedtheirrationale.

4Impact:Increasedthermalstress

Summary:

Therearecurrentlynowell-researchedmethodstodirectlyassistseabirdswith thermalstress,andmoreinformationisneededonhowthermalstresscanimpact seabirdsandhowlocalconservationactioncanmitigatetheseimpacts.Ifthermal stressbecomessocommonorextremethatitthreatenstheviabilityofa population,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention EvidenceofEffectiveness

Makenew colonies more attractiveto encourage birdsto colonise

Provide additional resourcesto helpseabirds thermoregula te (e.g.artificial pools)

Provide additional shelteror protection from extreme weather (heatwaves)

Severalactionshavebeentrialledacrossauk (andotherseabird)speciestoencourage colonisation,withvariablesuccess,including theuseofdecoys,acousticcues,smellsand improvedhabitat.Themostnotablesuccess hasbeentousedecoystoencourage F.arctica tocolonisenewareas,otheractionshavehad variablesuccessdependingoncontextand species.

R S T

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

3 4 3

Fewtrialsonseabirdsandnoneonauks. Additionalshelterhasbeenshowntoprotect cormorantsfromheatwaves,butmoreresearch isneededbeforethisactioncanbegenerally recommended.

NA NA NA

2 3 3

Intervention EvidenceofEffectiveness

Translocate the populationto amore suitable breeding area

Knowntobebeneficialinotherseabirdgroups, butevidenceforauksislimited.Atleastone successfultranslocationof F.arctica hasbeen carriedout,butwhetheritisgenerally advisableisuncertain.

3 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 1studyintheevidencebasefocussesonauks,37onother seabirdsand6onotherbirds. Strength(S): Theevidencebasewascomprisedof 44studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(heatwaves)

Relevance(R): 0studiesintheevidencebasefocusonauks,1onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof1study. Ofthese1wasconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T): 1studyincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,0hadapublishedmethodology,and1justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R):1studyintheevidencebasefocussesonauks,14onotherseabirds and0onotherbirds.Strength(S):Theevidencebasewascomprisedof15studies. Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclearmetric foreffectiveness. Transparency(T): 14studiesincludedwerepublishedandpeerreviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthegrey literature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

5Impact:Negativechangesinvegetation

Summary:

Whiletherearelimitedtrialsonseabirds,thereareseveralconcreteexampleswhere localmanagementhasincreasedproductivityeveninrelativelylargebreeding populations.

Intervention EvidenceofEffectiveness

R S T

Remove problematic vegetation

Removingvegetationhasbeenshowntobenefit severalseabirdspecies,buttheamountof evidenceislimitedinauks.Removalof problematicvegetationhasresultedinan increasein F.arctica breedingsuccessat severalsitesinScotland.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Removeproblematicvegetation

Relevance(R): 2studiesintheevidencebasefocusonauks,9onotherseabirds and5onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese12wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 16studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,13hadapublished methodology,and13justifiedtheirrationale.

6Impact:Reducedpreyavailabilityduringbreedingseason

Summary:

Severallocalactionsmayassistbreedingpopulationsonasmallscale,butdirect interventiononalargescaleislikelytobeextremelydifficult.Generalconservation actionstoprotectfishstocksandlocalmarineareasmaybethemosteffective method.Ifapopulationislikelytosuffermajorlosses,evenwithconservationhelp, thentranslocationscouldbeconsidered.

Artificially incubateor hand-rear chicksto support population

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Limited evidenceinauks,thoughcaptive F.arctica and F.cirrhata havebeensuccessfullyhand-reared.

Severalactionshavebeentrialledacrossauk (andotherseabird)speciestoencourage colonisation,withvariablesuccess,including theuseofdecoys,acousticcues,smellsand improvedhabitat.Themostnotablesuccess hasbeentousedecoystoencourage F.arctica tocolonisenewareas,otheractionshavehad variablesuccessdependingoncontextand species.

Trialledonmanyseabirdspecies.Limited evidenceforeffectivenessinauks,andall knownstudiesareon F.arctica.Typicallyvery labourintensiveanddifficultgiventheremote andinaccessiblebreedingcoloniesofauks. Likelyonlyplausibleforsmallpopulations.

Knowntobebeneficialinotherseabirdgroups, butevidenceforauksislimited.Atleastone successfultranslocationof F.arctica hasbeen carriedout,butwhetheritisgenerally advisableisuncertain.

Details: Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 6studiesintheevidencebasefocusonauks,34onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T): 26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 1studyintheevidencebasefocussesonauks,37onother seabirdsand6onotherbirds. Strength(S): Theevidencebasewascomprisedof 44studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 5studiesintheevidencebasefocusonauks,11onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 1studyintheevidencebasefocussesonauks,14onother seabirdsand0onotherbirds. Strength(S): Theevidencebasewascomprisedof 15studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hada clearmetricforeffectiveness. Transparency(T): 14studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,11had apublishedmethodology,and9justifiedtheirrationale.

7Impact:Reducedpreyavailabilityduringnon-breedingseason

Summary:

Inpelagicspecies,localinterventiontoassistpopulationsislikelytobedifficultor impossible.Generalconservationactionstopreservefishstocksandprotectmarine areasarelikelythemosteffectiveconservationactionsavailable.

Intervention EvidenceofEffectiveness

Further

protections atseato preserve foodstocks

Additionalprotectiontosupportpreystockscan indirectlybenefitmanyseabirdspecies,and limittheimpactofclimatechange.

R S T

1 3 3

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Furtherprotectionsatseatopreservefoodstocks

Relevance(R): 0studiesintheevidencebasefocusonauks,1onotherseabirds and8onotherbirds. Strength(S): Theevidencebasewascomprisedof9studies. Ofthese7wereconsideredtohaveagoodsamplesize,and3hadaclearmetricfor effectiveness. Transparency(T): 9studiesincludedwerepublishedandpeerreviewed,ofwhich2wereliteraturereviewsormeta-analyses,0werefromthegrey literature,and0wereanecdotal.Ofthestudiesincluded,3hadapublished methodology,and6justifiedtheirrationale.

1Long-tailedDuck (Clangulahyemalis

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (89%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(8%).

Currentbreedingareathatis likelytobecomemoresuitable (3%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: WinteringpopulationsinEuropehave declinedduetoclimatechange-drivenchangesinpredationinbreedingareas outsideofEurope.

NegativeImpact: Rangeexpansionofredfoxesfollowingmilderwintershas ledtopredationofducksmuchfurthernorththanpreviously,andmaybe threateningtheviabilityofnorthernpopulations.

NeutralImpact: Competitionwithnon-nativegobieshascausedlong-tailed duckstoswitchprey,thoughtherehasbeennoobservedchangeinmortality orcondition.Gobyinvasionmayhavebeenassistedbyclimatechange,though currentlythisisspeculative.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Thisspeciesisnumerousandhasalargecircumpolarrange,butsurveys suggestitisdecliningrapidlyespeciallyintheBaltic,mostlikelyduetoheavy bycatch.Anyadditionalpressurefromclimatechangeislikelytoexacerbate thesedeclines.

•Severalpopulationsoflong-tailedducksarestronglyrelianton Mytilusedulis formuchoftheyear. Mytilus spp areknowntobesensitivetoclimatechange, andwarmerconditionsarelikelytoresultinlowerqualityprey.The consequencesforlong-tailedducksareuncertain,butareverylikelynegative.

•KeywetlandbreedinghabitatsacrosstheArcticarerapidlydisappearingor changing.Theoverallimpactonlong-tailedduckpopulationsisunknown,but verylikelytobenegative.

•Speciesisknowntobesensitivetochangesinseatemperature,fluctuations inNAO,and,inparticular,thepresenceofseaice.Adeclineinseaiceislikely toresultinarangeshiftofwinteringpopulations,anditispossiblethatsucha redistributionhasalreadyoccurredintheBaltic.

•Long-tailedducksoftennestonlow-lyingareasnearwater,soaresensitive tofloodingduetoincreasedrainfallorwave-action.Anyincreaseinintensityor frequencyofstormsislikelytoimpactbreedingpopulations.

•Long-tailedduckstendtowinterinlargegroupsinrelativelysmallareas,so arevulnerabletomassmortalitythroughextremeevents.Evenlocalised climatechangeimpactsmayhavelargeconsequencesonthepopulationasa whole.

1.3Adaptivecapacity

•Populationswillmixduringnon-breedingseasonandthereislow differentiationbetweenpopulations.Thismaymakepopulationsmoreresilient toclimatechange,asimmigrationtosupportpopulationsismorelikely.

•Specieshasaverybroaddietthatvariesdependingonseasonand population.IntheBaltictheyhaverapidlyadjustedtheirdietinresponseto changesinpreyavailability.Thelossofonepreyspeciesisunlikelytoimpact populations,thoughnotethatsomepopulationsmaystillbereliantononeora fewkeyspeciesatsometimesoftheyear.

•Long-tailedduckseitherabandonorskipbreedinginparticularlyunsuitable years,preservingresources.Thiscouldbeadaptiveifconditionsbecomemore variableandamelioratetheimpactofpoorbreedingconditions.

•Femalelong-tailedducksgenerallyhavehighsitefidelityandareunlikelyto shiftbreedingareasquicklyinresponsetoclimatechange.

2HarlequinDuck (Histrionicushistrionicus

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (95%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(2%).

Currentbreedingareathatis likelytobecomemoresuitable (4%).

1.1.2Currentimpacts

attributedtoclimatechange:

NeutralImpact: Population hasredistributed,withsome populationsgrowingandothersshrinking,mostlikelyduetoshiftsinprey speciescausedbyclimatechange.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Harlequinducksaresensitivetostreamflowstrengthandvariabilityduring thebreedingseason;changesinfreshwaterflowcandisruptforagingandwash awaynests.Inpartsofitsrangewheretemperatureandprecipitationpatterns arelikelytochange,impactscouldbesignificant.

•Harlequinducksheavilyrelyonspecificmollusccommunities(e.g. Mytilus spp.),especiallyduringthenon-breedingseason.Manymarinemolluscspecies

areknowntobesensitivetoclimatechange,andwarmerconditionsarelikely toresultinreducedabundanceofkeypreyspecies.

•Harlequinduckstendtowinterinlargegroupsinrelativelysmallareas,so arevulnerabletomassmortalitythroughextremeevents.Evenlocalised climatechangeimpactsmayhavelargeconsequencesonthepopulationasa whole.

1.3Adaptivecapacity

•Fidelitytomoultingandwinteringlocationsisveryhigh,lesshightobreeding sites.Thismakesthespeciesvulnerabletochangesinwinteringsites, particularlytoextremeevents.

•Thespecieschangesbreedingsitesreadily,asdeterminedbylocal conditions.Redistributinginresponsetoclimatechangecouldpotentiallybuffer negativeimpacts.

3VelvetScoter (Melanittafusca)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (96%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(4%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NeutralImpact: Scoters arestartingtheirautumn migrationsignificantlylaterinresponsetochangingclimate.

NeutralImpact: Winteringpopulationshaveredistributed,mostlikelydue tolackofpreycausedatleastpartlybyclimatechange.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope

•ClimatechangehascontributedtodeclinesofscoterpopulationsinNorth America.Earlierspringsnowmelthaslikelyledtoatrophicmismatchandlower breedingsuccessinscoters.

1.2Sensitivity

•Thespeciesisnumerousandhasalargebreedingrange,buthassuffered rapiddeclinessince1970.Particularlysensitiveduringnon-breedingseasonas itgathersinhighconcentrationsinrelativelysmallareas(>90%oftheglobal populationwintersintheBaltic).Additionalpressurefromclimatechangeis likelytoacceleratethesedeclines.

•Manypopulationsofvelvetscotersrelyonseveralkeymolluscspeciesfor muchoftheyear,manyofwhichareknowntobesensitivetoclimatechange. Warmerconditionsandoceanacidificationarelikelytoresultinreduced abundanceofkeypreyspecies.

•Scoters,longtailedducksandeidershaveshowndeclinesduringhistorical regimeshiftsinmarineecosystems;theyarelikelysensitivetofuturechanges inmarineecosystems.

•KeywetlandbreedinghabitatsacrosstheArcticarerapidlydisappearingor changing.Theoverallimpactonvelvetscotersisunknown,butverylikelytobe negative.

•Oftennestsonlow-lyingareasnearwater,soissensitivetofloodingdueto increasedrainfallorwave-action.Anyincreaseinintensityorfrequencyof stormsislikelytoimpactbreedingpopulations.

•Velvetscoterstendtowinterinlargegroupsinrelativelysmallareas,soare vulnerabletomassmortalitythroughextremeevents.Evenlocalisedclimate changeimpactsmayhavelargeconsequencesonthepopulationasawhole.

•RecentobservationsandanecdoteshavereportedlargegroupsofnonbreedingscotersintheBaltic,manyinpoorcondition.Thismayindicatehigh levelsofstressorlackofhigh-qualityprey.Asthishasnotbeenobserved previously,thismaybearesultofclimatechange.Furtherresearchisneeded toclarifythecauseofthisandthelong-termimpactonthespecies.

1.3Adaptivecapacity

•Analysesoflayingdatesshowthereislittleplasticityinresponsetochanges intemperature,butthereissomevariationacrossandwithinpopulations.

•SpecieshasshownflexibilityinwinteringsitesinNorthAmerica,inpart predictedbyyear-to-yearchangesinseatemperatureandfluctuationsinNAO. Speciesislikelytoshiftwinteringsitesinresponsetoclimatechange,and thereforebuffernegativeeffects.

4CommonScoter (Melanittanigra)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (94%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(5%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange:

NeutralImpact: Wintering populationshaveredistributed, mostlikelyduetolackofpreycausedatleastpartlybyclimatechange.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•ClimatechangehascontributedtodeclinesofscoterpopulationsinNorth America.Earlierspringsnowmelthaslikelyledtoatrophicmismatchandlower breedingsuccessinscoters.

1.2Sensitivity

•ThereissomeevidencethatpopulationsintheBaltichavedeclined

substantially,buttheseareunsubstantiatedandmayinsteadindicate populationshiftstotheNorthSea.Ifthespeciesisindeeddeclining,climate changeislikelytoexacerbatethesedeclines.

•Manypopulationsofcommonscotersrelyonseveralkeymolluscspeciesfor muchoftheyear,manyofwhichareknowntobesensitivetoclimatechange. Warmerconditionsandoceanacidificationarelikelytoresultinreduced abundanceofkeypreyspecies.

•Scotershaveshowndeclinesduringhistoricalregimeshiftsinmarine ecosystems,theyarelikelysensitivetofuturechangesinmarineecosystems.

•KeywetlandbreedinghabitatsacrosstheArcticarerapidlydisappearingor changing.Theoverallimpactonscoterpopulationsisunknown,butisverylikely tobesignificant.

•Oftennestsonlow-lyingareasnearwater,soissensitivetofloodingdueto increasedrainfallorwave-action.Anyincreaseinintensityorfrequencyof stormsislikelytoimpactbreedingpopulations.

•Therearerecordsofcommonscotersinrecentwrecksalongthecoastofthe UK.Theextentandseverityofthesewrecksisunknown,butmaysuggestthat commonscotersarevulnerabletoextremeclimateevents,andmaybe significantlyimpactedbymorefrequent,ormoreextreme,storms.

•Recentobservationsandanecdotalreportshavereportedlargegroupsof non-breedingscotersintheBaltic,manyinpoorcondition.Thismayindicate highlevelsofstressorlackofhigh-qualityprey.Asthishasnotbeenobserved previously,thismaybearesultofclimatechange.Furtherresearchisneeded toclarifythecauseofthisandthelong-termimpactonthespecies.

1.3Adaptivecapacity

•Ifsuitablehabitatisavailable,commonscotershaveonoccasioneither temporarilyorpermanentlycolonisednewareas.Howeveringeneraltheyhave highsitefidelityandareunlikelytoshiftbreedingareasquicklyinresponseto climatechange.

•ThereissomeevidencethewinteringpopulationintheBalticisredistributing totheNorthSea.Howevertheextentofthisshiftisuncertainandthecauseis unknown.

•Veryvarieddietwhichvariesbypopulationandbyyear.Mostlikelytobe determinedbypreyabundance.Thelossofoneorafewpreyspeciesisunlikely tohaveasignificantimpact.

5Red-breastedMerganser

(Mergusserrator)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (92%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(7%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Red-breastedmergansershavelowlyingnests,whicharevulnerableto flooding.Sealevelriseorincreasedwaveactionfromstormscouldimpact breedingpopulations.

1.3Adaptivecapacity

•Red-breastedmergansersarecapableofestablishingorre-establishing coloniesifconditionsaresuitable.Breedingrangeseemstobeslowlyexpanding southinwesternEurope.

6RedPhalarope (Phalaropusfulicarius)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (93%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(6%). Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•InAlaskaredphalaropesnowlaysmallereggsonaverage,presumablydue tolowercondition.Thisislikelyduetodelayedsnowmeltduetohigher precipitation,despitethegeneralwarmingtrend.

•AcrossCaliforniaredphalaropeshavedeclinedacrosstheirwinteringareas. Thisislikelyduetochangesinoceancurrentsanddeclinesinpreyabundance.

•PopulationsaroundAlaskahavedeclinedinsomeareas,orpossibly redistributed,duetochangesinseaicecoverandinkeycopepodpreyspecies.

1.2Sensitivity

•ThespeciesissensitivetochangesinArctictern(Sternaparadisaea) populations.ItreliesonpredatoralarmwarningfrombreedingArcticterns,and localisedpopulationshavedecreasedrapidlyinsomebreedingcoloniesin GreenlandintheabsenceofArcticterns.AnyclimatechangeimpactsonArctic terns(whicharedocumented)arelikelytohaveanimpactonphalaropes.

•Thespeciesisrestrictedtohigh-latitudewettundraareas,whichare predictedtoconsiderablydecreaseinareaoverthenextcentury.Insomeparts ofitsrange,suchhabitatisalreadydisappearing.

•SomerecentmortalitiesinpopulationsoutsideEuropehavebeenlinkedto unusuallywarmweather,andthiscouldbeexacerbatedbyclimatechange.

•Populationsizes,trendsandthreatsarenotwellunderstood.Probablylargest threatsareclimatechange,predationbyfoxesandpollution.Anychangein populationsizeorimpactsarenotlikelytobedetectedrapidly.Carryingout conservationactionislikelytobechallenging.

•Speciesissensitivetomanythreats,includingdisturbancebyforestrywork, shiptraffic,bycatch,windfarmsandheavytourism.Nestabandonmentis commonwhendisturbed.Conservationinterventionmaythereforebedifficult.

•Phalaropesfrequentlygatherinlargegroupsinrelativelysmallareas,soare vulnerabletomassmortalitythroughextremeevents.Evenlocalisedclimate changeimpactsmayhavelargeconsequencesonthepopulationasawhole.

1.3Adaptivecapacity

•PhalaropesinAlaskaareknowntochangetheirlayingdateinresponseto changesinsnowmelt.NoknownstudyonphenologyinEurope.

•Specieshaslowsitefidelityoverall;redphalaropesreadilychangebreeding sitesdependingonconditions.Speciescouldpotentiallyshiftbreedingsitesin responsetoclimatechange.

•Redphalaropeseitherabandonorskipbreedinginparticularlypooryears, preservingresources.Thiscouldbeadaptiveifconditionsbecomemorevariable andamelioratetheimpactofpoorbreedingconditions.

7Red-neckedPhalarope (Phalaropuslobatus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (91%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(7%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts attributedtoclimatechange:

Neutral Impact: Redneckedphalaropeshaveshifted northinFinland,themostsoutherlypopulationsaredecliningwhilenortherly populationsareincreasing.Thisshiftisincorrelationwithclimatechange,but theunderlyingmechanismisnotcertain.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•AstudyinAlaskafoundthatphalaropeshavechangedtheirlayingdatein responsetochangesinsnowmelt.

•PhalaropeshaverespondedtochangesinoceanicpatternsintheIndian oceanandchangedtheirforagingareasandpatternsinresponse.

1.2Sensitivity

•Verylittleisknownaboutseveralaspectsofthisspecies’ecology.Thestatus andtrendsofpopulationsarelargelyunknown,andsoanyimpactsofclimate changewillbedifficulttoidentify,andeffectiveconservationactionwillbe challenging.

•Historicalchangesinweatherpatternscausedseverepopulationcrashes acrossAmerica,EuropeandAsia,manypopulationssufferedenormous mortalityandlocalnear-extinctions.Impactwaslikelyduetoheavydepletion ofplanktonpreyspecies.

•Phalaropesappeartohavelimitedcapacitytochangepreyspecies,andare heavilydependentonsomekeyhigh-energyspeciesduringthebreedingperiod. However,thisislikelytovarydependingonthepopulation.

•KeywetlandbreedinghabitatsacrosstheArcticarerapidlydisappearingor changing.Theoverallimpactonphalaropesisunknown,butverylikelytobe negative.

•Phalaropesfrequentlygatherinlargegroupsinrelativelysmallareas,soare vulnerabletomassmortalitythroughextremeevents.Evenlocalisedclimate changeimpactsmayhavelargeconsequencesonthepopulationasawhole.

•ThespeciesissensitivetochangesinArctictern(Sternaparadisaea) populations.ItreliesonpredatoralarmwarningfrombreedingArcticterns,and localisedpopulationshavedecreasedrapidlyfromsomebreedingcoloniesin GreenlandintheabsenceofArcticterns.AnyclimatechangeimpactsonArctic terns(whicharedocumented)arelikelytohaveanimpactonphalaropes.

1.3Adaptivecapacity

•Phalaropesareknowntochangetheirlayingdateinresponseto environmentalchange,includingrecentchangesinclimate.

•Phalaropesundergolongmigrations,whichareenergeticallydemanding. Differentpopulationsusedifferentmigrationstrategiesandhaveadaptedfor differentmigrationchallenges.Thismaymeanthespeciesisflexibleinits migrationstrategyandmayrespondtoclimatechange,butalsothatthe processishighlyoptimised.Changesine.g.winddirectionorstrengthcould havelargeimpacts.

•Red-neckedphalaropeseitherabandonorskipbreedinginparticularly unsuitableyears,preservingresources.Thiscouldbeadaptiveifconditions becomemorevariableandamelioratetheimpactofpoorbreedingconditions.

•Specieshaslowsitefidelityoverall;red-neckedphalaropesreadilychange breedingsitesdependingonconditions.Speciescouldpotentiallyshiftbreeding sitesinresponsetoclimatechange.

8Steller’sEider (Polystictastelleri)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100): Whilethisspeciesdoes occasionallybreedinEurope, recentassessmentshave concludedthesepopulations arenotpermanentandare generallyatverylowdensities. Assuch,nohabitatsuitability assessmentwascarriedout.

1.1.2Currentimpacts attributedtoclimatechange: NeutralImpact: Many Steller’seidershavechanged winteringareafromtheBaltic totheWhiteSea,mostlikelyduetodecreasesinseaice.Thismayalsobe associatedwithanoverallpopulationdecline,butthisisuncertain.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Thisspecieshasalargepopulationandalargerange,butisdeclining globally.InEuropetheoveralltrendisunclear,therehavebeendrasticdeclines intheBaltic,butthismaybeduetoredistributionstootherareas,inparticular thenorthcoastofRussia.Anyexistingdeclinesarelikelytobeexacerbatedby climatechange.

•Eidershaveshowndeclinesduringhistoricalregimeshiftsinmarine ecosystems,theyarelikelytobesensitivetofuturechangesinmarine ecosystems.

•Eidersareground-nestersandvulnerabletopredationbyfoxesandother mammals.Othereiderspecieshavesufferedincreasedpredationasaresultof climatechange.WhilethishasnotbeenobservedinSteller’seiders,any increaseinpredationcouldhavesignificantimpactsonpopulations.

•Manyofthespecies’keylife-historytraitsareunknown.Manyimpactstothe populationareunlikelytobedetectedquickly,andconservationactionislikely tobechallenging.

•Eidersformlargeraftsespeciallyinthenon-breedingseason,makingthem particularlyvulnerabletomassmortalityevents.Evenlocalisedclimatechange impactsmayhavelargeconsequencesonthepopulationasawhole.

•KeywetlandbreedinghabitatsacrosstheArcticarerapidlydisappearingor changing.Theoverallimpactoneiderpopulationsisunknown,butverylikelyto benegative.

•Eidershaveavarieddietofinvertebratesbutmanypopulationsarestrongly relianton Mytilus spp.andgastropodsformuchoftheyear. Mytilus spp.and gastropodsareknowntobesensitivetoclimatechange,andwarmerconditions arelikelytoresultinreductionofkeypreyspecies.Inaddition,eidersshowa preferenceforforaginginkelpbeds,andanyimpactstothesemayhavesevere negativeconsequencesforforagingeiders.

1.3Adaptivecapacity

•Whilethespeciesisgenerallyconsideredtohavehighsitefidelitytomoulting andwinteringsites,ithasdemonstratedrangeshiftsinresponsetoclimate change.LargenumbershaveredistributedtonorthernRussiaasseaicehas decreasedoverrecentdecades.

•Eiderseitherabandonorskipbreedinginparticularlyunsuitableyears, preservingresources.Thiscouldbeadaptiveifconditionsbecomemorevariable andamelioratetheimpactofpoorbreedingcondition.

9CommonEider (Somateriamollissima)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (80%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(18%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts

attributedtoclimatechange:

PositiveImpact: Milder winterandsummerweather haveresultedinbetteraverageadultcondition,andthereforebetterbreeding success.Insomeareasthishasresultedinlocalpopulationsincreases.

NeutralImpact: Eidershaveshiftedtheirphenologyinresponsetomilder wintersandlayearlier.

NegativeImpact: Duetoalackofseaicedrivenbyclimatechange,polar bearsarebecomingmorenumerousaroundbirdcoloniesduringthesummer andaremoreheavilypredatingoneiderpopulations.

PositiveImpact: Earliermeltofseaiceinspringhasresultedinadecrease inpredationbyArcticfoxes,astheycannotaccessbreedingcolonieswithoutthe presenceofseaice.

PositiveImpact: Earliermeltofseaiceinspringhasresultedinanincrease ineiderpopulationdensity,aseidershaveearlierandlongeraccesstohighqualityprey.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundancealongthecoastof Brittany,thecoastofBelgiumandalongthesouthcoastofNorwayandSweden.

1.1.3Predictedchangesinkeypreyspecies:

•CommoneiderssufferincreasedpredationfromArcticfoxesduetoprey switchingfollowingacollapseinlemmingbreedingcyclesinnorthernCanada.

•InadditionCanadianpopulationshavesufferedduetochangesinweatherin thebreedingseason,especiallyincreasedrain,eitherdirectlythroughexposure orindirectlythroughchangesinpredation.

1.2Sensitivity

•Thisspecieshasalargepopulationandalargerange,butisdecliningin severalpartsofitsrange.KnowntobedecreasingrapidlyintheBaltic,climate changecouldbeoneoftheunderlyingcausesbutthisisuncertain.

•Highprecipitationandwindintensityreducechicksurvival,likelythrough directmortalityfromexposureandduetoincreasedforagingdifficulty. Precipitationispredictedtoincreasewithclimatechangeacrossnorthern Europe,andthereforelikelytoheavilyaffectchicksurvival.

•Oftennestsonlow-lyingcoasts,soissensitivetofloodingduetoincreased rainfallorwave-action.Anyincreaseinintensityorfrequencyofstormsislikely toimpactbreedingpopulations.

•Eidershaveavarieddietofinvertebratesbutmanypopulationsarestrongly relianton Mytilusedulis formuchoftheyear. Mytilus spp.areknowntobe sensitivetoclimatechange,andwarmerconditionsarelikelytoresultinlower qualityprey.Theeffectofthisoneidersisuncertain,butisverylikelynegative.

•Eiderstendtowinterinlargegroupsinrelativelysmallareas,soare vulnerabletomassmortalitythroughextremeevents.Evenlocalisedclimate changeimpactsmayhavelargeconsequencesonthepopulationasawhole.

•Eidershaveshowndeclinesduringhistoricalchangesinseatemperatureand fluctuationsinweatherpatterns,particularlyaffectingthesurvivaland distributionofwinteringpopulations.Theyarelikelysensitivetofuturechanges inmarineecosystems.

•Eidersareparticularlysensitivetodiseaseoutbreaks,badyearscanclaimup to99%ofoffspring,andoutbreaksseemtohavealongtermeffectonfemale survivalrate.Anychangeindiseasedynamicsduetoclimatechangeislikelyto

havesignificantimpacts.

•Warmerandcalmerwinters,withearlierbreak-upofseaice,typicallyresult inbetterconditionadultsandmoreadultscommittingtobreedinginthe followingyear.Manywinteringareas(particularlyintheBalticandSvalbard)are likelytobecomemilderduetoclimatechange,whichmaybenefiteider populations.However,seaicealsoprovidesimportantrestingareasforeiders duringthewinter,soadrasticreductioninseaicemayhavecounteracting negativeeffects.

•Whileclimatechangemayhavesomepositiveimpactsforcommoneiders, itdoesnotmeanthatpopulationswillnecessarilyincreaseinresponsetoclimate change.Recentresearchhasfoundotherpressures,inparticularpredationby nativeandnon-nativepredators,mayessentiallyoverridethepositiveeffectsof climatechange,whichappeartobesmalloverall.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasepopulationextinctionrisk.

1.3Adaptivecapacity

•Eiderseitherabandonorskipbreedinginparticularlyunsuitableyears, preservingresources.Thiscouldbeadaptiveifconditionsbecomemorevariable andamelioratetheimpactofpoorbreedingconditions.

•ThereislowmigratoryconnectivitybetweenmanypopulationsinEurope (thoughthisisnotuniversal),andmanypopulationswillmixinthenon-breeding season.Thiscouldbeadaptive,aslowconnectivityisassociatedwithgreater flexibilityandhigherresponsivenesstochange.

•Femalecommoneidersaretypicallyhighlyfaithfultobreedingsites;extreme breedingphilopatryoffemaleducksmeansitisunlikelypopulationswillshiftin responsetoclimatechange.

•Historicallyeidershaveexpandedtheirrange,andcolonisednewareassuch asIrelandandNWEnglandintheearly20thcentury.Thissuggestsif populationsgrowandconditionsaresuitabletheneiderscancolonisenewareas.

•Whilesomepopulationsappeartohavechangedtheirphenology,other studieshavefoundchangesinlayingdatearenotrelatedtoweatherconditions. Plasticityseemstovarybetweenpopulations.

10KingEider (Somateriaspectabilis)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%). Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundanceonthewestcoastof SvalbardandaroundtheKaninPeninsulaandthesouthBarentsSea.

1.1.4ClimatechangeimpactsoutsideofEurope

•Increaseinicebreak-up,andincreasedvariabilityofbreak-up,causedby climatechangehasresultedinsignificantdamagetobenthicpreyandhascaused localshiftsinpreyavailability.Currentlythishasonlyasmallimpactonking eiders,butimpactscouldbecomesignificantinthefuture.

1.2Sensitivity

•Eidershaveshowndeclinesduringhistoricalregimeshiftsinmarine

ecosystems,theyarelikelysensitivetofuturechangesinmarineregimes.

•Wetlandsprovideimportantbreedinggroundsforthisspecies.Remote sensingandimaginghasshownfluctuationsinlakesinSiberia,withmanylakes disappearingandothersappearing.Theimpactonpopulationsisunknown,as theareaisdifficulttostudybutthepotentialimpactisverylarge.

•Kingeiderstendtowinterinlargegroupsinrelativelysmallareas,soare vulnerabletomassmortalitythroughextremeevents.Evenlocalisedclimate changeimpactsmayhavelargeconsequencesonthepopulationasawhole.

•Kingeidersarevulnerabletomassmortality,particularlyduringmigration.

Hundredsofthousandsofindividualshavebeenrecordeddyingfollowing unexpectedre-freezingofseaice.Changeorvariabilityofconditionsduring migrationperiodcouldhavesignificantimpactsonthepopulation.

•Kingeidersmaybesensitivetothelossofseaice,asitprovidesimportant roostingsitesduringwinterandsupportsmarinealgaeandbenthicinvertebrate prey.Whileimpactsofthelossofseaicehavenotbeenobservedoneidersso far,itisapotentialfutureimpact.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Verylowsitefidelitytobreedingareas(especiallyinmales),butalsofew documentedexamplesofbreedinginnovelareas,andnodocumentedrecords ofpermanentcolonisation.Overallitseemsunlikelythisspecieswillrangeshift rapidlyinresponsetoclimatechange.Highsitefidelitytowinteringareas,and evenlocalchangestothesesitesmayhavesignificantimpactonpopulations.

•Kingeidershaveavarieddiet,andcandivetogreaterdepthsthanmany othermarineducks.Theylikelycouldswitchtoalternativepreyorforaging strategiesifclimatechangechangesavailabilityofprey.

•Kingeidershavevariedmigrationpathwaysandstrategieswhichvary betweenindividualsandbetweenyears.Thisplasticitylikelyprovidessome resiliencetoclimatechange,aseiderscouldchangetheirmigrationstrategyin responsetolocalconditions.

•Kingeidershavelowmigratoryconnectivity(populationswillmingleduring non-breedingseason),andaweakgeneticstructure.Thismaybeadvantageous inresponsetoclimatechange,aslocaladaptationislowandmigrationplasticity ishighinkingeiderswhichmayallowthemtorespondrapidlytochange.

•Eiderseitherabandonorskipbreedinginparticularlyunsuitableyears, preservingresources.Thiscouldbeadaptiveifconditionsbecomemorevariable andamelioratetheimpactofpoorbreedingcondition.

Potentialactionsinresponse toclimatechange:Ducksand Phalaropes(Anatidaeand Scolopacidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increaseinmammalpredation

Summary: Invasivemammalsareamajorthreattomanyseabirdpopulations,andassuch thereisawell-establishedliteratureonmammalexclusion,managementand eradicationdetailingeffectivemethodsandcasestudies.However,therearemore limitedoptionswhenthemammalianpredatorinquestionisitselfaconservation target,orisnoteasilymanaged.Nevertheless,formanysituationsthereare several,well-researched,actionsavailablethatcanbenefitseabirdpopulations effectively.

Intervention EvidenceofEffectiveness

R S T

Manage/ eradicate mammalian predators

Strongevidencethatpredatormanagementcan assistseabirdpopulationsunderheavy predationpressure,ifcarriedouteffectively. Variousseaduckshavebeenshowntobenefit frompredatorcontrol,especiallytargeting rodentsandmustelids.Largerpredators,such asbearsandfoxes,aremoredifficulttodeter, andotheractionsaremorelikelytobeviable and/oreffective.

Trialledextensivelyonmanyseabirdgroups, mostlywithsuccess,thoughdependsonthe speciesandthedesignofthebarrier.Some trialsonduckshaveshownlimitedbenefits, butgenerallyquiteminorandforlimited species.Giventheremote,dispersednature ofmanyduckandphalaropenestingsites,it maybedifficulttocarrythisoutatscale.

Fewtrialsonseabirds,andnoneforducks andphalaropes.Existingevidencesuggests thisactioncanbebeneficialandreduceegg/ chickpredation,andcouldbeapossible actionifotherformsofpredatormanagement arenotviableorpermitted.

2 4 4

2 4 3

Repel predators with acoustic, chemicalor visual deterrents

Thisisahypotheticalaction.Wefoundno recordsofthisaction’seffectivenessfor seabirds. NA NA NA Use supplementa ryfeedingto reduce predation

Veryfewtrialsonseabirds,andnoneon ducksandphalaropes.Nostudieshaveshown thisactioniseffective. 1 4 3

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Manage/eradicatemammalianpredators

Relevance(R):1studyintheevidencebasefocussesonducksandphalaropes,45 onotherseabirdsand3onotherbirds.Strength(S):Theevidencebasewas

comprisedof52studies.Ofthese44wereconsideredtohaveagoodsamplesize, and34hadaclearmetricforeffectiveness.Transparency(T):52studiesincluded werepublishedandpeer-reviewed,ofwhich5wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,24hadapublishedmethodology,and28justifiedtheirrationale.

Physicallyprotectnestswithbarriersorenclosures

Relevance(R):0studiesintheevidencebasefocusonducksandphalaropes,12on otherseabirdsand6onotherbirds.Strength(S):Theevidencebasewascomprised of18studies.Ofthese16wereconsideredtohaveagoodsamplesize,and12had aclearmetricforeffectiveness.Transparency(T):17studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,11hadapublishedmethodology,and12justifiedtheir rationale.

Reducepredationbytranslocatingpredators

Relevance(R):0studiesintheevidencebasefocusonducksandphalaropes,2on otherseabirdsand2onotherbirds.Strength(S):Theevidencebasewascomprised of4studies.Ofthese4wereconsideredtohaveagoodsamplesize,and3hada clearmetricforeffectiveness.Transparency(T):4studiesincludedwerepublished andpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthe studiesincluded,2hadapublishedmethodology,and3justifiedtheirrationale.

Usesupplementaryfeedingtoreducepredation

Relevance(R):0studiesintheevidencebasefocusonducksandphalaropes,1on otherseabirdsand3onotherbirds.Strength(S):Theevidencebasewascomprised of4studies.Ofthese4wereconsideredtohaveagoodsamplesize,and4hada clearmetricforeffectiveness.Transparency(T):4studiesincludedwerepublished andpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthe studiesincluded,1hadapublishedmethodology,and4justifiedtheirrationale.

1NorthernGannet

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (62%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(37%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts attributedtoclimatechange:

NeutralImpact: Gannets areundertakinglongerforaging trips,mostlikelyinresponsetopreyshortagesduetoclimatechange.Although thislikelyincreasestheenergeticcostsofforaging,therehavesofarbeenno observedimpactsonbreedingsuccessormortality.

PositiveImpact: Gannetshaveestablishednewcoloniesaskeyprey specieshaveshiftedfurthernorth.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceinthesouthernIrishSea andonthenorthcoastofFrance.

1.1.4ClimatechangeimpactsoutsideofEurope:

•MarineheatwavesinNorthAmericahaveresultedinwide-spreadbreeding failureandinsomecasestemporarydesertionofcolonies.Mostlikelybecause ofpreyshortages,butheatstresscouldplayaroleaswell.Itisdifficultto

attributeindividualclimateeventstoclimatechange,butheatwavesare becomingmorecommonandmoreextreme,andwilllikelycontinuetodoso.

•Lackofkeypreyspecies(mackerel)duetowarmeraveragemarine temperaturesandover-exploitationhascausedlowbreedingsuccessina southernpopulationofgannetsinCanada.

1.2Sensitivity

•Heatwavesareknowntocauseheatstressingannetchicksandadults.So farthishasnotbeenobservedtosignificantlyaffectpopulationsinEurope,but heatwavesinotherpartsoftheirrangehavecausedbreedingfailuresand temporarycolonydesertion.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Gannetsoccasionallyestablishnewcolonies,therearemultiplerecordsof themcolonisingorrecolonisingareasfollowingenvironmentalchangeor removalofthreats.

•Individualsareoftenveryloyaltobreedingsites.Onceadultsestablishanest sitetheywillreturnformanyyears,whichreducestheircapacitytoadaptto changeatbreedingsites.

•Dietisvariableacrosstheirrangeandovertime.Longtermstudieshave noticedshiftsinprimarypreyspeciesoverseveraldecades,whichindicates somecapacityforpopulationstoshiftdiet.

•Gannetshavebeennotedtochangephenology,butnotincorrelationto changesinconditions.Overallthereislittlechangeinmigrationtiming,andthe underlyingcausesforanyobservedchangesisuncertain.

•Gannetsforageoverlargeareasandshowconsiderableflexibilityinforaging behaviour,localchangesinpreyavailabilityareunlikelytohavealargeimpact.

2EuropeanShag (Gulosusaristotelis)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (44%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(60%).

Currentbreedingareathatis likelytobecomemoresuitable (6%).

1.1.2Currentimpacts attributedtoclimatechange:

NeutralImpact: Shags haveadvancedtheirlaying date,mostlikelydueto changesinmarinetemperaturesandsubsequentlyinpreyavailability.

NeutralImpact: Thedietcompositionofshagshaschangedagreatdeal, likelyinresponsetoclimatechangedrivenchangesinthemarineecosystem.

NegativeImpact: Extremestormsduringtheshagbreedingseasonhave ledtowide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.

NegativeImpact: Recentdeclinesinshagpopulationsbecauseofhighadult mortalityaremostlikelybecauseofincreasinglyseverewinterstorms.

NeutralImpact: Shagsbreedlateraswintershavebecomecolder.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea,the north-eastoftheUK,thenortherncoastofSpainandalongthecoastofBrittany

1.2Sensitivity

•Shagsonlyhavepartiallywater-prooffeathers,andassuchareproneto water-loggingandhypothermiainwet,coldweather.Extremeeventsoften resultinwide-scalemortality(‘wrecks’)andbreedingfailure,assuchpredicted increasesinstormfrequencyandintensitycouldhavesevereimpactsonshags.

•Whenfoodisplentifulshagpopulationsalsooftenrecoverquitequickly,and sooftenfollowa“boomandbust”cycle.Thismaybehelpfulinresponseto climatechangeaspopulationscanrecoverquickly,butalsomakesthem sensitivetorapidchangeaspopulationscanbecomelocallyextinctquickly.

•Whileinmanypopulationsshagshaveavarieddiet,inotherstheyare heavilydependentonsandeels,saitheorherring.Previousdecreasesinprey specieshaveledtolowerbreedingsuccess.Forsomepopulations,anychange tokeypreyavailabilityduetoclimatechangecouldhavesevereconsequences.

•Shagstypicallynestonlow-lyinghabitats,oftenonlyafewmetresfromthe water-line,whicharevulnerabletofloodingandbeingwashedaway.Sea-level riseoranincreaseinwaveactionduringthebreedingseasoncouldhave significantimpactsonbreedingcolonies.

•Manyshagpopulationsheavilyrelyonkelpforesthabitats,especiallyduring thebreedingseason.Manykelpforestsknowntobeimportanttoshagsare eitherdecliningduetoclimatechangeorarelikelytobeveryvulnerableto climatechange.Sofar,theimpactofthedeclineinkelpforestsonshagsis unknown,butispotentiallysevere.

•Shagsarelikelytobesensitivetoheatwaves,astheyarecommonly observedgularflutteringonhotdays,andabsorbheatveryeffectively.Other speciesofshagsareknowntobeimpactedbyheatwaves,whichcausepoor breedingseasonsandincreasedmortality.Heatwavesarelikelytobecomemore frequentandextremeduetoclimatechange.

•Thespeciesisdeclininginmanypartsofitsrange.Thecausesbehindthese declinesarenotwellunderstood,butclimatechangeandextremeweather eventsareonelikelycause.

1.3Adaptivecapacity

•Shagsareknowntochangetheirphenology,probablyincorrelationto resourceavailability.Thisislikelytobuffersomeeffectsofclimatechangeas shagsmaychangebreedingtimingtomatchpreyavailability.

•Foragingstrategyandbehaviourvariessubstantiallyacrosspopulationsand individuals.Ingeneralshagsareflexibleandgeneralistintermsofpreyand foraginghabitat,butindividualsareoftenspecialised.

3GreatCormorant

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (76%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(23%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange:

NeutralImpact: Cormorantsthatmigrateto coastalareasduringthewinterarenowmigratinglater,mostlikelyduetoless andlatericeonfreshwaterfeedingareas.

PositiveImpact: Cormorantsareexpandingtheirrangeduetoincreased availabilityofprey,inlargepartduetodeclinesincompetingmarinepredators, whichinturnarepartiallydrivenbyclimatechange.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea,onthe coastofBrittany,thenorthofDenmark,andacrosstheEnglishChannel.

1.1.4ClimatechangeimpactsoutsideofEurope:

•CormorantsinGreenlandhavespreadtheirsummerrangefurthernorth, mostlikelyduetowarmerseatemperaturesandchangesinfoodavailability. However,thishasalsolikelyincreasedthecostsofmigration,ascormorants havefurthertotraveltoreachice-freeareasinwinter.

1.2Sensitivity

•Cormorantpopulationtrendsarecorrelatedwithlocalseasurface temperature,itseemslikelythatinmanyareaswarmerwaterswillbenefit cormorants.Sensitivityisthereforelikelytobelowinmanyareas.However, thereislikelyalimittonorthernexpansionascormorantscannotforage effectivelyinareaswithshortperiodsofdaylight.

•Cormorantsaresensitivetoextremeweatherevents,includingextremecold periodsandhighrainfall.Cormorantsonlyhavepartiallywater-prooffeathers, andassucharepronetowater-loggingandhypothermiainwet,coldweather. Thenorthernedgeoftheirrangeislikelysetbywintertemperatures,andthe durationofseaandlakeice.

1.3Adaptivecapacity

•Followinghistoricaldeclinesandseverallocalextinctions,thisspecieshas greatlyrecoveredfollowingincreasedprotectionanddecreasedpersecution,and hasrecolonisedmanyareasofitspreviousrange.Itthereforeseemslikelythat cormorantscanredistributeandestablishnewpopulationsinresponseto climatechange.

•Cormorantsgenerallyhavelowsitefidelity,andmassrelocationsare relativelycommon.Itseemslikelythatcormorantscanrapidlyredistributeto moresuitableareasifnegativeimpactsoccur.

•Thisspecieshasadiversediet,butthisvariesdependingonpopulation. Somepopulationsvariouslypreyonupto20species,dependingonavailability, whereasothersareheavilyononeorafewspecies.Theeffectofalossofakey preyspeciesislikelytovarydependingonareaandpopulation.

u r o p e a n s hag

Potentialactionsinresponse toclimatechange:Gannets andCormorants(Sulidaeand Phalacrocoracidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)increasesforagingdifficultyand/ormortality

Summary:

Severallocalactionsmaybepossibletolimitmortalityorincreaserecoveryona smallscale,butforlargerpopulationseffectivelocalactionisdifficult.Supporting thepopulationinmoregeneralways(increasingadultsurvival,limitingchick mortality)maybethemosteffectivemethod.

Intervention EvidenceofEffectiveness R S T

Provide supplementa ryfood duringthe breeding season

Trialledonmanyseabirdspecies.Limited evidenceforeffectivenessingannetsand cormorants,thoughithasbeenfoundtohave someminorbenefitsfornon-European gannets.Typicallyverylabourintensiveand difficult,andprobablyonlyplausibleforsmall populations.

3 4 3

Provide supplementa ryfood duringthe non-breeding season

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

NA NA NA

Rehabilitate sickor injuredbirds

Forothergroupsoflong-lived,largebirds, rehabilitationhasbeenshowntobeeffective (particularlyinraptors).However,examplesin seabirdsarescarceandtheoverall effectivenessformostspeciesisunknown. Thefewreportsofrehabilitatinggannets, cormorantsandshagsnotethattreatmentis difficultasthesespeciesareeasilydistressed, especiallycormorants,andpronetodisease incaptivity.Moreinformationisneeded,but generallytheconsensusistreatmentis difficultandlabour-intensive.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Providesupplementaryfoodduringthebreedingseason

Relevance(R): 3studiesintheevidencebasefocusongannetsandcormorants,13 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof16studies.Ofthese10wereconsideredtohaveagoodsamplesize, and14hadaclearmetricforeffectiveness. Transparency(T): 16studiesincluded werepublishedandpeer-reviewed,0werefromthegreyliterature,and0were anecdotal.Ofthestudiesincluded,13hadapublishedmethodology,and4justified theirrationale.

Rehabilitatesickorinjuredbirds

Relevance(R): 1studiesintheevidencebasefocusongannetsandcormorants,2 onotherseabirdsand4onotherbirds. Strength(S): Theevidencebasewas comprisedof7studies.Ofthese4wereconsideredtohaveagoodsamplesize,and 1hadaclearmetricforeffectiveness. Transparency(T): 7studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,5hadapublishedmethodology,and5justifiedtheir rationale.

2Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)causesnestdestruction

Summary: Whilethereareseverallocalactionsthatmaypreventormitigatelocalnest destruction,theyhavenotbeentrialledwidelyandwide-spreadevidencetosupport theiruseiscurrentlylacking.Ifchangesinextremeweatherthreatenstheviability ofapopulation,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention

Alterhabitat toencourage

birdstoleave anarea

Fewtrialsonseabirdsandnoneongannetsor cormorants,hasbeeneffectiveinsomeother seabirdgroups.Thisactioncouldbe investigatedforcormorantsandshags,asthis actionismoreviableforspecieslowersite fidelityandareaswithotheravailablebreeding habitatnearby.

Artificially incubateor hand-rear chicksto support population

Install barriersto prevent flooding

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.No documentedexamplesofhand-rearingin cormorantsorgannets.

Whilelikelytopreventfloodingthereis currentlynoevidenceavailableonthisaction’s effectivenessinrelationtoseabird conservation.

Makenew colonies more attractiveto encourage birdsto colonise

Severalactionshavebeentrialledacross seabirdspeciestoencouragecolonisation,with variablesuccess,includingtheuseofdecoys, acousticcues,smellsandimprovedhabitat. Thereislimitedevidenceforcormorantsand gannets,butseveralexamplesexistwhere cormorantshavebeensuccessfullyencouraged tonewareaswithartificialvocalisationsand decoys.

NA NA NA

NA

NA

Provide

2 5 3 Translocate the populationto amore suitable breeding area

Knowntobebeneficialinotherseabirdgroups,

Details: Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,2 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof2studies.Ofthese2wereconsideredtohaveagoodsamplesize,and 0hadaclearmetricforeffectiveness. Transparency(T): 2studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,2hadapublishedmethodology,and1justifiedtheir rationale.

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,40 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof40studies.Ofthese9wereconsideredtohaveagoodsamplesize, and19hadaclearmetricforeffectiveness. Transparency(T): 26studiesincluded werepublishedandpeer-reviewed,0werefromthegreyliterature,and0were anecdotal.Ofthestudiesincluded,17hadapublishedmethodology,and4justified theirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,38 onotherseabirdsand6onotherbirds. Strength(S): Theevidencebasewas comprisedof44studies.Ofthese31wereconsideredtohaveagoodsamplesize, and18hadaclearmetricforeffectiveness. Transparency(T): 44studiesincluded werepublishedandpeer-reviewed,ofwhich1wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,30hadapublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(flooding)

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,0 onotherseabirdsand3onotherbirds. Strength(S): Theevidencebasewas comprisedof3studies.Ofthese1wasconsideredtohaveagoodsamplesize,and 2hadaclearmetricforeffectiveness. Transparency(T): 3studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,3hadapublishedmethodology,and3justifiedtheir rationale.

Provideartificialnestingsites

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,53 onotherseabirdsand1onotherbirds. Strength(S): Theevidencebasewas comprisedof54studies.Ofthese50wereconsideredtohaveagoodsamplesize,

and33hadaclearmetricforeffectiveness. Transparency(T): 53studiesincluded werepublishedandpeer-reviewed,ofwhich2wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,33hadapublishedmethodology,and27justifiedtheirrationale.

Repair/supportneststosupportbreeding

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,2 onotherseabirdsand1onotherbirds. Strength(S): Theevidencebasewas comprisedof3studies.Ofthese1wasconsideredtohaveagoodsamplesize,and 1hadaclearmetricforeffectiveness. Transparency(T): 3studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,1hadapublishedmethodology,and3justifiedtheir rationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 0studiesintheevidencebasefocusongannetsandcormorants,15 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof15studies.Ofthese13wereconsideredtohaveagoodsamplesize, and9hadaclearmetricforeffectiveness. Transparency(T): 14studiesincluded werepublishedandpeer-reviewed,ofwhich1wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,11hadapublishedmethodology,and9justifiedtheirrationale.

1EuropeanHerringGull

(Larusargentatus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (84%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(10%).

Currentbreedingareathatis likelytobecomemoresuitable (5%).

1.1.2Currentimpacts attributedtoclimatechange: NegativeImpact: Changes inmercurycycling(dueto increasedseatemperatures)hasledtoincreasedexposuretomercury,with negativeimpactsonherringgullhealth.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope •Increasedfloodingduetosealevelrisehasledtothereductionordestruction ofseveralpopulationsintheUS.

1.2Sensitivity

•Herringgullsoftennestinlow-lyingorexposedareas,whichmakesthem vulnerabletostormsandflooding.Morefrequentextremestormsorflooding duringthebreedingseasoncouldhavesevereeffectsonpopulations.

•Duringheatwaves,herringgulls’eggsandchickshavebeenobserved sufferinghighstressandmortality.Theoverallimpactofthisonthepopulation isunknown,butitappearsherringgulls,especiallyinexposedareas,are vulnerabletoheatwavesandincreasedfrequencyandintensityislikelytolower breedingsuccess.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Extremelyvariablediet,andabletoexploitmanyavailablefoodsources. Thisislikelytomakeherringgullsmoreresilienttoclimatechange,butnote thatmanyindividualpopulationsarespecialisedandarehighlyreliantononeor afewsourcesoffood(e.g.humandiscards).Plasticityisthereforelikelytovary acrosspopulations.

•Herringgullsarealsoadeptatusingurbanenvironmentswhichmaybuffer populationsifnaturaldietorhabitatislimited.

•Undertherightcircumstances,herringgullscanestablishnewcolonies. Whiletheytendtohavesomesitefidelity(especiallyadults),theyhavebeen observedtocolonisenewareasovertimeifnewareasareparticularlyhighqualityorifpreviousareaisdisturbed.

2Audouin’sGull (Larusaudouinii)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (68%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(32%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanyimpacts ofclimatechangeonthis species.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundanceonthesouthcoastof Portugal.

1.2Sensitivity

•Themajorityofthepopulationisconcentratedatrelativelyfewbreeding sites.ThismakestheEuropeanpopulationasawholevulnerabletochange, includingfromclimatechange.

•Audouin’sgullsarehighlysusceptibletootherthreats,inparticularbycatch andpredatordisturbance.Thespeciesiscurrentlysharplydecliningmostlikely duetochangesinfishingdiscardpracticeandhighpredationrates.Any

additionalpressurefromclimatechangeislikelytoexacerbatethesedeclines.

•Thespeciesishighlysensitivetochangesinfoodavailability.Therecanbe rapidpopulationgrowthinyearsofpreyabundance,butrapiddeclinescanoccur inpooryears.Ifclimatechangecontributestodeclinesinkeypreyspecies,then gullpopulationsarelikelytobeheavilyimpacted.

•Audouin’sgullsfrequentlynestinlow-lyingorexposedareas(e.g.saltpans), whichmakesthemvulnerabletostormsandflooding.Morefrequentextreme stormsorfloodingduringthebreedingseasoncouldhavesevereeffectson populations.

1.3Adaptivecapacity

•Followingchangesinfishingpracticeandotherconservationmeasures,this previouslyendangeredspeciesrecoveredandexpandedsignificantly.Itappears tobeabletogrowinnumberandcolonisenewareaswhenconditionsare suitable,indicatinghighdispersalability.

3CaspianGull (Laruscachinnans)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (97%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(3%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Caspiangullshaveavarieddietandarelikelyabletopreyswitch.Change, orloss,ofpreyspeciesduetoclimatechangeisunlikelytohavewide-spread impact.

•Caspiangullshaverecentlyexpandedtheirrangeintoseveralnewareasof Europeandthespeciesseemsabletodisperseandexploitsuitablehabitat effectively.

4LesserBlack-backedGull

(Larusfuscus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (61%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(27%).

Currentbreedingareathatis likelytobecomemoresuitable (12%).

1.1.2Currentimpacts attributedtoclimatechange: PositiveImpact: Positive Impact:Increasedprey availabilityduringthebreedingseasonhasledtopopulationgrowth. 1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundanceonthesouthcoastof Norway,thesouthernIrishSeaandalongtheBrittanyCoast.

1.2Sensitivity

•Lesserblack-backedgullstypicallynestinlow-lyingorexposedareas,which makesthemvulnerabletostormsandflooding.Morefrequentextremestorms orfloodingduringthebreedingseasoncouldhavesevereeffectsonpopulations.

•Duringheatwaves,lesserblack-backedgulleggsandchickshavebeen observedsufferinghighstressandmortality.Theoverallimpactofthisonthe populationisunknown,butitappearsgulls,especiallyinexposedareas,are vulnerabletoheatwavesandincreasedfrequencyandintensityislikelytolower breedingsuccess.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Extremelyvariablediet,andabletoexploitmanyavailablefoodsources. Thisislikelytomakelesserblackbackedgullsmoreresilienttoclimatechange, butnotethatmanyindividualpopulationsarespecialisedandarehighlyreliant ononeorafewsourcesoffood(e.g.humandiscards).Inparticular,the subspecies Larusfuscusfuscus intheBalticareheavilyreliantonspawning herringduringthebreedingseason.Plasticityisthereforelikelytovaryacross populations.

•Lesserblackbackedgullsarealsoadeptatusingurbanenvironmentswhich maybufferpopulationsifnaturaldietorhabitatislimited.

•Undertherightcircumstances,lesserblackbackedgullscanestablishnew colonies.Whiletheytendtohavesomesitefidelity(especiallyadults),they havebeenobservedtocolonisenewareasovertimeiftheyareparticularly high-qualityorifpreviousareaisdisturbed.

5GlaucousGull (Larushyperboreus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (77%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(23%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: There hasbeenincreasedpredation bypolarbears,mostlikelyduetoreductioninseaiceandthereforealackof alternativeprey.Insomeyearsthishasseverelyaffectedbreedingsuccess.

NegativeImpact: Climatechangeislikelycontributingtohigher concentrationsofcontaminantsingestedbyglaucousgulls.Theoveralleffecton thepopulationisunknown,butpresumablynegative.

NegativeImpact: Climatechangehascontributedtoarangeshiftin severalhelminthparasites,whichhasledtoglaucousgullsbeingexposedto novelparasites,aswellasincreasedparasiteload.Effectonpopulationis unknown,butpresumablynegative.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundancealongtheKaninPeninsula andsouthernBarentsSea.

1.1.4ClimatechangeimpactsoutsideofEurope

•Glaucousgullcoloniesdisplayhigherratesofcannibalismandlowerbreeding successinresponsetohigherseatemperatures.Thisispresumablyduetolack ofmarineprey,andislikelytobeexacerbatedwithfurtherclimatechange.

1.2Sensitivity

•Chicksaresusceptibletoweather-relatedmortality,especiallyifseverewet weatheroccursduringhatchingandfirstweekpost-hatch.Changes,especially anincrease,inprecipitationduringkeybreedingperiodsmayhavelargeimpacts onchicksurvival.

•GlaucousgullshavehighaccumulationofPOPcompounds,andcurrent modellingsuggestspotentialexacerbationofPOPsandmercuryinmarinefood websduetoclimatechange(i.e.,increasingtemperatures).Currentlyno negativeimpactshavebeenobserved,buthigherlevelsofbioaccummulationin thefutureisapotentialrisktogullhealth.

•Avianfluhasbeenrecentlyrecordedinsomepopulationsofglaucousgulls; warmerweatherinthefuturemaycontributetooutbreaks.

•Competingspecies,suchasherringgulls,areshiftingtheirrangesnorth,in partinrelationtoclimatechange.Thismayleadtocompetitioninthefutureif rangesoverlap.

1.3Adaptivecapacity

•Verydiversediet,consistingoffish,marineinvertebrates,birdeggsand young,smallbirdsandmammals,carrion,refuse,seaweed,berries.Lossofone foodsourceisunlikelytohaveamajorimpactonmostpopulations.

6GreatBlack-backedGull

(Larusmarinus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (87%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(26%).

Currentbreedingareathatis likelytobecomemoresuitable (4%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: Higher seatemperaturescorrelatewith lowerbreedingsuccess.Mechanismunknown,butlikelymediatedthroughprey availability.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea,aswell asalongtheNorwegiancoast,southerncoastoftheUKandtheBrittanyCoast.

1.2Sensitivity

•Greatblack-backedgullsaredeclininginareasoftheeasternAtlantic,likely duetoreductionsinfishingdiscards.Anyadditionalimpacts,suchasfrom climatechange,arelikelytoexacerbatethisdecline.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Extremelyvariablediet,andabletoexploitmanyavailablefoodsources. Thisislikelytomakegreatblackbackedgullsmoreresilienttoclimatechange, butnotethatmanyindividualpopulationsarespecialisedandarehighlyreliant ononeorafewsourcesoffood(e.g.humandiscards).Plasticityistherefore likelytovaryacrosspopulations.

•Greatblack-backedgullshavehistoricallyshownrangeexpansionswhen pressureshavebeenalleviated,thereisevidencetheycancoloniseorrecoloniseareasiftheyareparticularlyhigh-qualityorifpreviousareasare disturbed.

•Greatblack-backedgullsoccasionallyuseurbanhabitatsandresources, whichmaybufferpopulationsifnaturaldietorhabitatislimited.

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%). Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: Ivory gullsareheavilyreliantonsea iceforbreedingandhunting,recentdecreasesinseaiceareleadingtorapid changesinpopulationsizeandrange.

NegativeImpact: Asasecondaryimpactofseaiceloss,ivorygullsface morecompetitionfromotherivorygullsandfromotherspeciesforresources.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

•Climatechangeisknowntohaveseveralotherimpactsinotherpartsofthe speciesrange,inparticularthroughchangingwinterfoodsupplies,increasing competitionwithothermarinebirds,andincreasedpredationduetoincreased accesstopreviouslyisolatedcolonies.

1.2Sensitivity

•Ivorygullsarehighlydependentonseaice;declinesinpopulationsizeand rangehavebeenlinkedinseveralareastodecreasesinseaice,particularly acrosstheCanadianArcticandGreenland.

•Ivorygullsbreedinextremelyremotecolonieswhichlimitsdisturbancerisk, butalsomakesmonitoringandanypotentialconservationactionsdifficult.

•Ivorygullsaresensitivetoextremeclimaticevents;extremeheavyrainfall andwindstormshaverecentlyledtototalbreedingfailuresinGreenland.If climatechangeresultsinmoreextremeormorefrequentextremeweather,this islikelytohavesevereimpactsonivorygullpopulations.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Ivorygullshaveavarieddietandareopportunisticfeeders.Thelossofone preyspeciesisunlikelytohaveamajorimpactonthepopulations.

•Thereishighconnectivityandgeneflowamongpopulations,suggestingthat populationsaregeneticallydiverseandthereissignificantexchangebetween populations.Thiscouldincreaseresiliencetoclimatechangeasadaptive variationandimmigration/emigrationaremorelikely.

8Black-leggedKittiwake

(Rissatridactyla)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (60%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(40%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Decreasedpreyavailabilitydue towarmerseashasledtolowerbreedingsuccess.

NeutralImpact: Kittiwakediethaschangedsignificantlyduetoclimatechangedrivenshiftinpreyassemblage.However,sofarthishasnotresultedin anydemonstratedchangeinbreedingsuccess.

NeutralImpact: Kittiwakepopulationshaveshiftedtheirrangeinresponse tochangesindistributionofkeypreyspecies.

NeutralImpact: Climatechangehascontributedtoarangeshiftinseveral helminthparasites,whichhasledtokittiwakesbeingexposedtonovelparasites, aswellasincreasedparasiteload.Effectonpopulationisunknown,butmost likelynegative.

NegativeImpact: Higherseatemperaturescorrelatewithlowerbreeding success.Mechanismunknown,butpotentiallymediatedthroughprey availability.Alternativetheoriessuggestfisherypressurehasbeenalarge

contributingfactor.

NegativeImpact: Kittiwakecolonieshavedeclinedduringperiodsofrapid oceanwarming.Mechanismunknown,butlikelyduetorapidchangesinmarine ecosystemsandpreyavailability.

NegativeImpact: Extremestormsduringthenon-breedingseasonhave ledtomassmortalityofkittiwakes(‘wrecks’).

NegativeImpact: Extremestormsduringthekittiwakebreedingseason haveledtowide-spreadnestdestruction,nestingfailureandanetreductionin annualpopulationproduction.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea, throughouttheEnglishChannelandalongtheBrittanyCoast.

1.1.4ClimatechangeimpactsoutsideofEurope

•RecentheatwavesintheNorthPacifichaveresultedinmassmortalityand wide-spreadbreedingfailureatkittiwakecolonies.

1.2Sensitivity

•Thereappearstobestrongvariationinregionalresponsestoclimatechange. TheimpactsofclimatechangeonkittiwakesinScotlandhavenotbeenseen elsewhereintheUK.Inaddition,thereissomedebateonwhetherthedrastic declinesofkittiwakecoloniesinScotlandwereprimarilyduetoclimatechange orfisheries.Thesensitivityofdifferentpopulationstoclimatechangeislikelyto vary.

•LargekittiwakecoloniesinthenorthAtlanticaresupportedindirectlyby copepods(astheyformthebasisofthemarinefoodchain).Projectionsof copepodabundancesuggesttheywillrangeshiftnorth,withlargeimpactson seabirdcolonies.

•Manykittiwakecoloniesaredependentonthetimingofavailabilityofkey preyspecies,suchassandeels.Keypreyspeciessuchassandeelsareknown tobesensitivetowarmingtemperatures,whichmayresultinaphenological mismatch.

•Kittiwakesforageatorneartheseasurface.Ifclimatechangeresultsin morefrequentorprolongedstormsorpreymovingintodeeperwater,itislikely tohavesignificantimpactsonkittiwakeforaging.

1.3Adaptivecapacity

•Thereissometentativeevidencethatkittiwakescanadaptivelychangetheir phenologybasedonstudiesinSvalbard.PopulationsinScotlandhavealso changedtheirlayingdate,possiblyrelatedtoconditionsinbreedingandnonbreedingareas.

•Undertherightcircumstances,kittiwakescanestablishnewcolonies.While theytendtohavesomesitefidelity(especiallyadults),theyhavebeenobserved tocolonisenewareasovertimeiftheyareparticularlyhigh-qualityorifprevious areaisdisturbed.

•Kittiwakesoccasionallyuseurbanhabitatsandresources,especiallywhere artificialnestinghabitatisavailable,whichmaybufferpopulationsifnaturaldiet orhabitatislimited.

9Sabine’sGull (Xemasabini)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Asahigh-Arcticspecies,itislikelythatSabine’sgullissensitivetoclimate changeastheArcticiscurrentlyundergoingrapidclimateandecological change.Howevernoimpactshavebeenobservedsofar.

•Therearegenerallyfewassessmentsofindividualpopulationsortheir relativestatus,soimpactsmaynotberecorded.

•Thereisevidencethatannualsurvivalisaffectedbyextremeclimaticevents

initstropical,non-breedingrange;thesemaybecomemorefrequentwith climatechange.

•Sabine’sgullstypicallynestinlow-lying,floodedareas,oftenverycloseto thehigh-tideline,whichmakesthemvulnerabletostormsandflooding.More frequentextremestormsorfloodingduringthebreedingseasoncouldhave severeeffectsonpopulations.

1.3Adaptivecapacity

•PopulationsofSabine’sgulloverlapandmeetduringthenon-breedingseason (lowmigratoryconnectivity).Becauseofthis,immigrationismorelikelyto bufferclimatechangeimpacts,andhighergeneticdiversityofpopulations meansadaptiveresponsetoclimatechangeismorelikely.

10Yellow-leggedGull

(Larusmichahellis)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (65%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(21%).

Currentbreedingareathatis likelytobecomemoresuitable (14%).

1.1.2Currentimpacts attributedtoclimatechange: NegativeImpact: Extreme stormsduringtherazorbill breedingseasonhaveledtowide-spreadnestdestruction,nestingfailureanda netreductioninannualpopulationproduction.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundanceonthesouthcoastof Portugal.

1.2Sensitivity

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Veryvariedandopportunisticdiet,includingfish,invertebrates,mammals, refuseandoffal,birdeggsandchicks.Yellow-leggedgullshavebeenobserved tochangetheirprimarypreyspeciesifonesourcebecomesunavailable.

•Undertherightcircumstances,yellow-leggedgullscanestablishnew colonies.Whiletheytendtohavesomesitefidelity(especiallyadults),they havebeenobservedtocolonisenewareasovertimeiftheyareparticularly high-qualityorifpreviousareaisdisturbed.

Potentialactionsinresponse toclimatechange:Gulls (Laridae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increaseincompetition

Summary:

Localactionstopreventormitigatetheeffectsofcompetitionarenotwell understood,andtheireffectivenessisunclear.Inmanycontextstheyarelikelyto bedifficultorimpossibletocarryoutonlargepopulations.Supportingpopulations moregenerally(increasingadultsurvival,limitingchickmortality)maybeamore appropriatestrategy.

Intervention EvidenceofEffectiveness

Protectnest sitesfrom competitors

Reduce competition byremoving competitor species

Rarelytrialledinseabirds,somebenefitsfound inothernon-seabirdgroups.Likelytobe difficultduetolarge,cosmopolitannatureof manycolonies;maybepossibleforspecies withspread-out,discretenest-sites.

Trialledmostlyonterns,butunclearifitis effectiveornot.Veryscarceevidenceforgulls, ithasbeentrialledbuttheoveralleffectiveness isunclear.Moreresearchneededifthisaction istobeconsideredasaviableaction.

R S T

Use supplementa

ryfeedingto reduce competition

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

NA NA NA

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Protectnestsitesfromcompetitors

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and5onotherbirds. Strength(S): Theevidencebasewascomprisedof7studies. Ofthese5wereconsideredtohaveagoodsamplesize,and2hadaclearmetricfor effectiveness. Transparency(T): 6studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,3hadapublishedmethodology,and4justifiedtheirrationale.

Reducecompetitionbyremovingcompetitorspecies

Relevance(R): 1studyintheevidencebasefocussesongulls,11onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof12 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and5hadaclear metricforeffectiveness. Transparency(T): 12studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,8hadapublishedmethodology,and7justifiedtheirrationale.

2Impact:Increaseinmammalpredation

Summary:

Invasivemammalsareamajorthreattomanyseabirdpopulations,andassuch thereisawell-establishedliteratureonmammalexclusion,managementand eradicationdetailingeffectivemethodsandcasestudies.However,therearemore limitedoptionswhenthemammalianpredatorinquestionisitselfaconservation target,orisnoteasilymanaged.Nevertheless,formanysituationsthereare several,well-researched,actionsavailablethatcanbenefitseabirdpopulations effectively.

Intervention EvidenceofEffectiveness R S T

Manage/ eradicate mammalian predators

Physically protectnests withbarriers orenclosures

Strongevidencethatpredatormanagementcan assistseabirdpopulationsifunderheavy predationpressure,andifcarriedout effectively.Severalsuccessfulexamplesin gulls.

Trialledextensivelyonmanyseabirdgroups, mostlywithsuccess,thoughdependsonthe speciesandthedesignofthebarrier.Some trialsongulls,inparticularonAudouin’sgull, haveshownbenefitsandloweredpredation.

Reduce predationby translocating predators

Fewtrialsonseabirds,andnoneforgulls. Existingevidencesuggeststhisactioncanbe beneficialandreduceegg/chickpredation,and couldbeapossibleactionifotherformsof predatormanagementarenotviable.

3

Repel predators with acoustic, chemicalor visual deterrents

Use supplementa ryfeedingto reduce predation

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

2

Veryfewtrialsonseabirds,andnoneongulls. Nostudieshaveshownthisactioniseffective.

NA NA NA

NA NA NA

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence.

R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Manage/eradicatemammalianpredators

Relevance(R): 2studiesintheevidencebasefocusongulls,43onotherseabirds and4onotherbirds. Strength(S): Theevidencebasewascomprisedof52 studies.Ofthese44wereconsideredtohaveagoodsamplesize,and34hada clearmetricforeffectiveness. Transparency(T): 52studiesincludedwere publishedandpeer-reviewed,ofwhich5wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,24had apublishedmethodology,and28justifiedtheirrationale.

Physicallyprotectnestswithbarriersorenclosures

Relevance(R): 3studiesintheevidencebasefocusongulls,9onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof18 studies.Ofthese16wereconsideredtohaveagoodsamplesize,and12hada clearmetricforeffectiveness. Transparency(T): 17studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,11hadapublishedmethodology,and12justifiedtheir rationale.

Reducepredationbytranslocatingpredators

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and2onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and3hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and3justifiedtheirrationale.

Usesupplementaryfeedingtoreducepredation

Relevance(R): 0studiesintheevidencebasefocusongulls,1onotherseabirds and3onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and4hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and4justifiedtheirrationale.

3Impact:Increasedexposuretopollutionandheavymetals

Summary:

Theeffectsofpollutionandheavymetalsareknowntohaveseriousconsequences forgulls,butdespitethistherearenocurrentactionsthatarewell-researched.Itis likelypreventionismoreeffectivethantreatment,sothemosteffectiveactionin manycasesistodetergulls(ifpossible)fromusingaheavilypollutedarea.

Intervention EvidenceofEffectiveness

Alterhabitat toencourage birdstoleave anarea

Reduce exposureto pollutants

Treatsickor injuredbirds affectedby pollution/ heavymetals

Verylimitedevidenceforseabirds,andnone forgulls.Severalsuccessfulexamplesofthis actioninterns,butmoreresearchneeded beforethisisconsideredasaviableoptionfor gulls.

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds(anddidnotinclude evidenceregardingtreatmentfollowingoil spills).Likelytoberesourceintensive.

R S T

2 2 3

NA NA NA

NA NA NA

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof2studies. Ofthese2wereconsideredtohaveagoodsamplesize,and0hadaclearmetricfor effectiveness. Transparency(T): 2studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and1justifiedtheirrationale.

4Impact:Reducedareaofbreedingorforaginghabitat

Summary:

Onalocalscale,providingartificialnestingsitescanbeaneffectivemethodof counteractingthisimpact,thoughtherearerelativelyfewtrialsongulls.Outsideof this,iflackofhabitatthreatenstheviabilityofapopulation,thenseveralactionsare availabletoencouragetranslocationofpopulationstosaferareas.

Intervention EvidenceofEffectiveness

Alterhabitat toencourage birdstoleave anarea

Fewtrialsonseabirdsandnoneongulls. Severaltrialsofthisactionhavebeen successfulandencouragedternstoshift breedingsites.However,thisactionislikely moreviableforspecieswithlowersitefidelity andareaswithotheravailablebreedinghabitat nearby.

Makenew coloniesmore attractiveto encourage birdsto colonise

Severaldifferentmethodshavebeentrialled extensivelyacrossotherseabirds,with variablesuccessdependingonmethodand species.Noevidencecurrentlyavailablefor gulls,theeffectivenessofdecoys,acoustic cues,smellsandimprovedhabitatiscurrently unknown.

Triedextensivelyonmanyseabirdspecies withsignificantbenefittomanyspecies. Artificialnestingsiteshavebeensuccessfully usedtosupportkittiwakepopulations,for othergullspeciesresultshavebeenmixedbut severalspecieshavebenefitedfromartificial nestingsites.

Knowntobebeneficialinotherseabird groups,butevidenceforgullsislimited. Severalfailedattemptshavebeenrecorded, andtoourknowledgenosuccessful translocationsofgullshavebeencarriedout.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof2studies. Ofthese2wereconsideredtohaveagoodsamplesize,and0hadaclearmetricfor effectiveness. Transparency(T): 2studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and1justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusongulls,38onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideartificialnestingsites

Relevance(R): 1studyintheevidencebasefocussesongulls,51onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof54 studies.Ofthese50wereconsideredtohaveagoodsamplesize,and33hada clearmetricforeffectiveness. Transparency(T): 53studiesincludedwere publishedandpeer-reviewed,ofwhich2wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,33had apublishedmethodology,and27justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 1studyintheevidencebasefocussesongulls,14onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

5Impact:Reducedpreyavailabilityduringbreedingseason

Summary:

Severallocalactionsmayassistbreedingpopulationsonasmallscale,butdirect interventiononalargescaleislikelytobeextremelydifficult.Generalconservation actionstoprotectfishstocksandlocalmarineareasmaybethemosteffective method.Ifapopulationislikelytosuffermajorlosses,evenwithconservationhelp, thentranslocationscouldbeconsidered.

Intervention EvidenceofEffectiveness

Artificially incubateor hand-rear chicksto support population

Makenew coloniesmore attractiveto encourage birdsto colonise

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Gullshave beensuccessfullyhand-reared,butonlyin verysmallnumbers.Likelytobedifficultfor manyspecies,especiallythosethatbreedin steep,inaccessiblehabitats.

Severaldifferentmethodshavebeentrialled extensivelyacrossotherseabirds,with variablesuccessdependingonmethodand species.Noevidencecurrentlyavailablefor gulls,theeffectivenessofdecoys,acoustic cues,smellsandimprovedhabitatis currentlyunknown.

Trialledonmanyseabirdspecies.Knownto bebeneficialforseveralgullspecies,but successvaries.Manygullswillscavengeany availablefoodsource,soitisfeasibleto providesupplementaryfood.However,as manygullpopulationsarealreadyrelianton discards,thereareethicalconcernsregarding wide-spreaduseofsupplementalfeedingto supportpopulations.

R S T

Translocate the populationto amore suitable breeding area

Knowntobebeneficialinotherseabirdgroups, butevidenceforgullsislimited.Severalfailed attemptshavebeenrecorded,andtoour knowledgenosuccessfultranslocationsofgulls havebeencarriedout.

3 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 2studiesintheevidencebasefocusongulls,38onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T): 26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusongulls,38onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 4studiesintheevidencebasefocusongulls,12onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 1studyintheevidencebasefocussesongulls,14onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

6Impact:Increasedparasiteload

Summary:

Treatmentandpreventionoptionsareavailableforsomeparasites,buttheyare generallyrarelytrialledonseabirds,andthebulkofavailableknowledgeisbasedon non-seabirdspecies.Carefulconsiderationandplanningisneededbeforeembarking onmass-treatmentofseabirdpopulations,toavoidunintendednegative consequences.

Intervention EvidenceofEffectiveness

R S T

Inoculation ortreatment against diseaseand parasites

Extensiveliteratureexistsfortreatmentof birdsingeneral,butlimitedexamplesfor seabirdsandnoneforgulls.Manytreatment andpreventionoptionsareavailable,butthose thathavebeentrialledhavelimitedsuccess,or evencausemoreharmthanbenefits,inwild seabirdpopulations.Theadvisabilityofthis actionlikelydependsonthespeciesand contextinquestion.Endoparasitetreatmentin seabirdsisparticularlyunder-researched.

1 5 4

Inoculationortreatmentagainstdiseaseandparasites

Relevance(R): 0studiesintheevidencebasefocusongulls,5onotherseabirds and29onotherbirds. Strength(S): Theevidencebasewascomprisedof34 studies.Ofthese25wereconsideredtohaveagoodsamplesize,and22hada

clearmetricforeffectiveness. Transparency(T): 34studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,21had apublishedmethodology,and26justifiedtheirrationale.

Summary:

Whilethereareseverallocalactionsthatmaypreventormitigatelocalnest destruction,theyhavenotbeentrialledwidelyandwide-spreadevidencetosupport theiruseiscurrentlylacking.Ifchangesinextremeweatherthreatenstheviability ofapopulation,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention EvidenceofEffectiveness R S T

Alterhabitat toencourage birdstoleave anarea

Fewtrialsonseabirdsandnoneongulls. Severaltrialsofthisactionhavebeen successfulandencouragedternstoshift breedingsites.However,thisactionislikely moreviableforspecieswithlowersitefidelity andareaswithotheravailablebreedinghabitat nearby.

Artificially incubateor hand-rear chicksto support population

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Gullshave beensuccessfullyhand-reared,butonlyinvery smallnumbers.Likelytobedifficultformany species,especiallythosethatbreedinsteep, inaccessiblehabitats.

3 2 1 Install barriersto prevent flooding

Whilelikelytopreventfloodingthereis currentlynoevidenceavailableonthisaction’s effectivenessinrelationtoseabirdconservation NA NA NA

7Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)causesnestdestruction

Makenew coloniesmore attractiveto encouragebirds tocolonise

Severaldifferentmethodshavebeentrialled extensivelyacrossotherseabirds,with variablesuccessdependingonmethodand species.Noevidencecurrentlyavailablefor gulls,theeffectivenessofdecoys,acoustic cues,smellsandimprovedhabitatis currentlyunknown.

Manually relocatenests

Thishasbeenreportedbypractitionersas aneffectiveactiontoassistseabirdsonlowlyingbeachesintheBaltic.However,toour knowledgetherearenobroad-scalestudies orreviewsofthisaction’seffectiveness.The riskofdisturbanceishigh,soislikelyonly anoptionasalastresort.

NA NA NA

Provide additional shelteror protectionfrom extreme weather (flooding)

Therearefewtrialsonseabirdspecies,most knownexamplesareonterns,andmost reportlittletonobenefitforbreeding populations.However,evidenceislimited andmoreresearchisneededonthisaction’s overalleffectiveness.Wefoundnopublished trialsongullspecies.

1

Provideartificial nestingsites

Triedextensivelyonmanyseabirdspecies withsignificantbenefittomanyspecies. Artificialnestingsiteshavebeensuccessfully usedtosupportkittiwakepopulations;for othergullspeciesresultshavebeenmixed butseveralspecieshavebenefitedfrom artificialnestingsites.

Repair/support neststo support breeding

Verylimitedevidenceforeffectivenessin seabirds,thoughknowntobeeffectivein otherbirds.Noknownexamplesingull species.

2

Translocatethe populationtoa moresuitable breedingarea

Knowntobebeneficialinotherseabird groups,butevidenceforgullsislimited. Severalfailedattemptshavebeenrecorded, andtoourknowledgenosuccessful translocationsofgullshavebeencarriedout.

3 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof2studies. Ofthese2wereconsideredtohaveagoodsamplesize,and0hadaclearmetricfor effectiveness. Transparency(T): 2studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and1justifiedtheirrationale.

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 2studiesintheevidencebasefocusongulls,38onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T): 26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusongulls,38onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(flooding)

Relevance(R): 0studiesintheevidencebasefocusongulls,0onotherseabirds and3onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and2hadaclearmetricfor

effectiveness. Transparency(T): 3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,3hadapublishedmethodology,and3justifiedtheirrationale.

Provideartificialnestingsites

Relevance(R): 1studyintheevidencebasefocussesongulls,51onotherseabirds and1onotherbirds.Strength(S): Theevidencebasewascomprisedof54 studies.Ofthese50wereconsideredtohaveagoodsamplesize,and33hada clearmetricforeffectiveness. Transparency(T): 53studiesincludedwere publishedandpeer-reviewed,ofwhich2wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,33had apublishedmethodology,and27justifiedtheirrationale.

Repair/supportneststosupportbreeding

Relevance(R): 0studiesintheevidencebasefocusongulls,2onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness.Transparency(T):3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and3justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 1studyintheevidencebasefocussesongulls,14onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

Intervention EvidenceofEffectiveness

R S T

Provide supplementary foodduring thebreeding season

Trialledonmanyseabirdspecies.Knowntobe beneficialforseveralgullspecies,butsuccess varies.Manygullswillscavengeanyavailable foodsource,soitisfeasibletoprovide supplementaryfood.However,asmanygull populationsarealreadyreliantondiscards, thereareethicalconcernsregardingwidespreaduseofsupplementalfeedingtosupport populations.

Provide supplementary foodduring thenonbreeding season

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.Whilepossible, especiallyforspeciesthatremainnearland, thesameconcernsapplyasduringthe breedingseason.Manygullpopulationsare alreadyreliantondiscards,andthereare ethicalconcernsregardingwide-spreaduseof supplementalfeedingtosupportpopulations.

Rehabilitate sickorinjured birds

Forothergroupsoflong-lived,largebirds, rehabilitationhasbeenshowntobeeffective (particularlyinraptors).However,examplesin seabirdsarescarceandtheoverall effectivenessformostspeciesisunknown. Therearefewsuccessfulreportsof rehabilitationingulls,butseveralnotable successesinterns,someofwhichinvolved successfultreatmentfollowingmass strandings.Moreinformationisneeded,but generallytheconsensusistreatmentis difficultandlabour-intensive.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 4studiesintheevidencebasefocusongulls,12onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Rehabilitatesickorinjuredbirds

Relevance(R): 0studiesintheevidencebasefocusongulls,3onotherseabirds and4onotherbirds. Strength(S): Theevidencebasewascomprisedof7studies. Ofthese4wereconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T): 7studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,5hadapublishedmethodology,and5justifiedtheirrationale.

1ArcticLoon (Gaviaarctica)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (96%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(3%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundancealongtheSwedishBaltic coast.

1.2Sensitivity

•Loonshaveastrongpreferenceforbreedingnearnutrient-poor,veryclear freshwater.Thereisstrongevidencethattheproductivityoflakesisincreasing acrossFenno-Scandinavia,whichhasresultedindecreasedwatertransparency, andthereforedecreasedforagingsuccessandconditionofloonchicks.

“Browning”offreshwaterlakeshasalsoledtoreducedbiomassofkeyfish species,butalsoashifttowardssmallerfish,whichcouldpotentiallyresultin

positiveornegativeeffectsforloons.Climatechangeislikelytoacceleratethis processandcouldhavesignificantimpactsonloonsinthefuture.

•Speciesissensitivetomanythreats,includingdisturbancebyforestrywork andtourism,shiptraffic,bycatchandwindfarms.Nestabandonmentis commonwhendisturbed.Conservationinterventionmaythereforebedifficult.

•Sensitivetofloodingduetostormsandincreasedwaveactionasloonstend tonestclosetowaterlevelinexposedareas.Anywaterlevelriseorincreasein waveactionislikelytohavesignificantimpactonbreedingpopulations.Nests arealsovulnerabletofloodingduetoheavyprecipitation,andassignificantrain eventsareexpectedtoincreaseinmanyareasduetoclimatechange,flooding eventscouldbecomemorefrequent.

1.3Adaptivecapacity

•Norelevantinformationcouldbeidentified.

Note:loons/diversandgrebesrelyheavilyonfreshwaterpreyandhabitats. Whilethesewereconsideredforthisassessment,wefocusedonmarinehabitats andprey.Estimatesofbreedinghabitatandpreylossarethereforebiased.

2CommonLoon (Gaviaimmer)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (96%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(2%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope

SeveralimpactsofclimatechangehavebeennotedinNorthAmerican populations,includingdecreasedbroodsize,changesinmigrationpatterns, increasedenergeticstressduetohighertemperatures,andanincreasein exposuretomercury.

1.2Sensitivity

•Loonnestsarevulnerabletofloodinggiventheirplacementattheshoreline’s edge.Assignificantraineventsareexpectedtoincreaseinmanyareasdueto climatechange,increasedfloodingcouldhavesignificantimpacts.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Feedsonawidevarietyofmarineandfreshwaterfish,andappearsto prey-switchreadily.Lossofoneorafewspeciesduetoclimatechangeis unlikelytosignificantlyimpactmostpopulations.

•Commonloonsfrequentlyreturntothesamebreedingsites,andshowstrong breedingsitefidelity.Inaddition,dispersalislowsonewareasarenot commonlycolonised.However,followingrepeatedbreedingfailuresseveral populationshaveabandonedprevioussitesandcolonisednewareas.This suggestssomepopulationsmayshiftinresponsetochangingclimate.

•Commonloonshavehighfidelitytowinteringsites,andtheyareunlikelyto respondquicklytochangeinconditionsinthesewinteringareas.Anymajor changetotheseareasmayhavesignificantimpactsonwinteringpopulations.

Note:loons/diversandgrebesrelyheavilyonfreshwaterpreyandhabitats. Whilethesewereconsideredforthisassessment,wefocusedonmarinehabitats andprey.Estimatesofbreedinghabitatandpreylossarethereforebiased.

3Red-throatedLoon (Gaviastellata)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (93%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(4%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundancealongthesouth-western SwedishcoastandtheBalticSea.

1.1.4ClimatechangeimpactsoutsideofEurope

•SeveralimpactsofclimatechangehavebeennotedinNorthAmerican populations,includingdecreasedbroodsize,changesinmigrationpatterns, increasedenergeticstressduetohighertemperatures,andanincreasein exposuretomercury.

1.2Sensitivity

•Loonshaveastrongpreferenceforbreedingnearnutrient-poor,veryclear

freshwater.ProductivityoflakesisincreasingacrossFenno-Scandinavia,which hasresultedindecreasedwatertransparency,andthereforedecreasedforaging successandconditionofloonchicks.“Browning”offreshwaterlakeshasalso ledtoreducedbiomassandsmallerbodysizeofkeyfishspecies,whichhave bothpositiveandnegativeconsequencesforloons.

•Somepopulationsofred-throatedloons(particularlyinIceland)relyon small,shallowpondsforfeedingandfornestingsites.Inhot,drysummers thesepoolscandryupandresultindifficultyintake-off,foragingand thermoregulation.Furtherhotter,driersummerscausedbyclimatechange couldhavesignificantimpactsonthesepopulations.

•Climatechangeathighlatitudescouldgreatlyreducetheareaofsuitable breedinghabitatforred-throatedloonsthatbreedintheseareas.Warmingcan leadtochangesinlakeice-coverageanddrainage,whichinturncanleadtothe temporaryorpermanentlossofkeytundrahabitatforbreedingloons.

•Red-throatedloonsaresensitivetodisturbance,humanactivitycanresultin manynestsbeingabandoned.Conservationinterventionduringthebreeding seasonmaythereforebedifficulttocarryoutwithoutdisturbingnestingbirds.

•Red-throatedloonsarealsosensitivetopredation,lowoverallbreeding successrateisoftenduetoheavypredation.Changeinpredatorrangeor abundanceduetoclimatechangeislikelytohavesignificantimpactsonloons.

•Nestsaresensitivetofloodingfollowinghighrainfallorheavystorms.Any increaseinextremeeventscouldsignificantlyimpactbreedingpopulations.

1.3Adaptivecapacity

•Red-throatedloonsfrequentlyreturntothesamebreedingsites,andshow somebreedingsitefidelity.However,whenconditionschangeseveral populationshaveabandonedprevioussitesandcolonisednewareas.This suggestssomepopulationsmayshiftinresponsetochangingclimate.

•Red-throatedloonshavehighfidelitytowinteringsites,andtheyareunlikely torespondquicklytochangeinconditionsinthesewinteringareas.Anymajor changetotheseareasmayhavesignificantimpactsonwinteringpopulations.

•Migrationofred-throatedloonsoftenvariesyeartoyearinresponsetowind andweatherconditions,thoughflexibilityislikelytobelimitedduetocomplex interactionofcarry-overeffectsandroleofstagedmigration.Loonsmaybeable tochangemigrationstrategytosomeextentinresponsetoclimatechange.

Note:loons/diversandgrebesrelyheavilyonfreshwaterpreyandhabitats. Whilethesewereconsideredforthisassessment,wefocusedonmarinehabitats andprey.Estimatesofbreedinghabitatandpreylossarethereforebiased.

4HornedGrebe (Podicepsauritus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (92%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(7%).

Currentbreedingareathatis likelytobecomemoresuitable (1%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Thespecieshasalargerange,andalargepopulation(thoughthepopulation inEuropeisrelativelysmall),butisdecliningrapidlyacrossmuchofitsrange.

Thecauseisunknown,previousresearchhasfoundlittletonoevidenceclimate changeiscontributingtodecline.However,additionalpressurefromclimate changeislikelytoexacerbateexistingdeclines.

•Speciesissensitivetodisturbance,sitesorwholeareascanbeabandonedif

thereisheavyhumanactivity.Conservationinterventionormonitoringis thereforedifficult.

•Hornedgrebesbuildeitherfloatingnestsornestsonlow-lyingrocksand beaches.Nestsarethereforevulnerabletofloodingcausedbyhighwindand waveaction,itcanbeasignificantsourceofmortality.Anychangesinlakeor coastalsealevelarelikelytohaveimpactsonbreedingpopulations.

1.3Adaptivecapacity

•Hornedgrebesfrequentlyreturntothesamebreedingsites,andshowsome breedingsitefidelity.However,whenconditionschangeseveralpopulations haveabandonedprevioussites.Thereappearstobesignificantinterchange betweenpopulations,andsomepopulationsmayshiftinresponsetochanging climate.

•Specieshasavarieddietoffreshwaterandmarinespecies.Changein availabilityofoneorafewspeciesisunlikelytohavesignificantimpactson mostpopulations.

Note:loons/diversandgrebesrelyheavilyonfreshwaterpreyandhabitats. Whilethesewereconsideredforthisassessment,wefocusedonmarinehabitats andprey.Estimatesofbreedinghabitatandpreylossarethereforebiased.

5Red-neckedGrebe

(Podicepsgrisegena)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (98%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(1%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•Sensitivetodisturbance;nestsarefrequentlyabandonedinpresenceof humanactivity.Maymakeconservationactionormonitoringmoredifficult.

•Sensitivetofloodingandwaveactionasnestsitesareoftennearthe water-lineandexposed.Insomeyearsthisisamajorcauseofnestandegg loss,andanyincreaseinsealevelorfrequencyofstormsmayhavesignificant impactsonnestingsites.

1.3Adaptivecapacity

•Red-neckedgrebesreadilychangebreedingsite,oftenchangingtheirsite eachyear.Insomecasestheywillevenchangenestsiteduringthebreeding season.Theycouldpotentiallyrapidlychangebreedingareasinresponseto climatechange.

•Hasavarieddietofbothfreshandsaltwaterspecies.Thelossofoneora fewspeciesisunlikelytosignificantlyimpactmostpopulations.

Note:loons/diversandgrebesrelyheavilyonfreshwaterpreyandhabitats. Whilethesewereconsideredforthisassessment,wefocusedonmarinehabitats andprey.Estimatesofbreedinghabitatandpreylossarethereforebiased.

Potentialactionsinresponse toclimatechange:Loons/ DiversandGrebes(Gaviidae andPodicipedidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpactsonauks.Thissectionis notgroupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecific tooneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.

Additionalnote: loons/diversandgrebesrelyheavilyonfreshwaterpreyand habitats.Whilethesewereconsideredforthisassessment,wefocussedheavilyon marinehabitatsandprey.

Wedidnotidentifyanycurrentimpactsofclimatechangeforthis group.

1Cory’sShearwater

(Calonectrisborealis)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NeutralImpact: New colonieshavebeenestablished outsideofthespecies’normalrange.Thecauseisuncertain,butlikelyrelated topreyrangeshiftsandwarmingconditions.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Cory’sshearwaterscansuffermass-mortalities,especiallyfollowingextreme stormsorhurricanesintropicalpartsoftheirrange.Changesinhowandwhere hurricanesoccurcouldhavesignificantimpactsonshearwaters.

•ExtremepositiveandnegativeNAOindicesdrasticallyimpactadultforaging

patterns,adultcondition,andchickcondition,verylikelybecauseofchangesin preyavailability.Extremefluctuationsarelikelytobecomemorecommoninthe future,andthereforemayheavilyimpactshearwaterbreedingpopulations.

•Cory’sshearwatersrelyonwindconditionstosoaranduseaslittleenergyas possible.Changesinwindstrength,directionandpatternscouldheavilyimpact energyuseandmigrationpaths.

•Cory’sshearwatershavehighbreedingsynchrony;themajorityofbirdsina populationwilllaytheireggsinashortperiodoftime.Iftemporalshiftsinkey preyavailabilityoccuritcouldhaveasignificantimpactonbreedingpopulations.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Analysisoflayingdateshasshownthat,regardlessofseatemperaturesand weatherconditions,thereislittlevarianceinCory’sshearwaterphenology.Itis unlikelytheywilladapttheirlayingdatetochangingconditions.

•Cory’sshearwatershowslittleplasticityinchoosingnestingsites,andcan evenchoosemaladaptivelyinthepresenceofpredators.Althoughitrecently hasestablishedinnorthernSpain,thisisbelievedtobearareevent.Highsite fidelitymeansitisunlikelytochangesitesasaresponsetoclimatechange.

•Cory’sshearwaterchangetheirforagingstrategyandpreyspeciesbasedon preyavailability.This,combinedwitharelativelyflexiblediet,islikelytomake themmoreresilienttoclimatechange.

2NorthernFulmar (Fulmarusglacialis)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (80%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(20%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange:

NeutralImpact: Warmer wintershaveresultedinlower adultsurvivalandlowerreproductivesuccessinthefollowingyear.Mechanism uncertain,butcouldberelatedtomarineproductivityortofrequencyand severityofstorms.

NegativeImpact: Higherseatemperaturestypicallycorrelatewithlower breedingsuccess.Mechanismunknown,butlikelymediatedthroughprey availability.Continuedwarmingmaycauselong-termdeclinesinpopulations.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea,the EnglishChannel,thesoutherncoastofNorwayandalongtheBrittanycoast.

1.2Sensitivity

•Fulmarsarepronetowrecksacrosstheirrange.Previouswreckshavebeen attributedtoacombinationofsustainedhighwinds,unusuallywarmwaters,and reducedfoodavailability,allofwhicharemorelikelytooccurmorefrequently duetoclimatechange.

•Fulmarsrelyonwindconditionstosoaranduseaslittleenergyaspossible. Changesinwindstrength,directionandpatternscouldheavilyimpactenergy useandmigrationpaths.

•Stormsarealsoknowntohavesomenegativeeffectsonfulmarbreeding successastheyleadtomoredifficultforagingconditionsandlowerbody condition.Changesinstormpatternsmayaffectfulmarbreedingsuccess,as wellascontributetowrecks.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

•Fulmarshavehighbreedingsynchrony;themajorityofbirdsinapopulation willlaytheireggsinashortperiodoftime.Iftemporalshiftsinkeyprey availabilityoccuritcouldhavesignificantimpactsonbreedingpopulation.

1.3Adaptivecapacity

•Atlanticpopulationhasexpandeddramaticallyinrangeandnumberduring last200years,likelydrivenbyincreaseinfisherydiscards.Speciesreadily colonisesnewareasiftheyaresuitable,whichislikelytohelpfulmarsadaptto climatechange.

•Juvenilesveryfrequentlydispersetoothercolonies,butoncebreedingthe specieshasveryhighsitefidelity.Althoughnewcoloniesareformedreadily, existingpopulationsareveryunlikelytorelocate.

•Veryvariablediet,evenwithincomparativelysmallarea.Different populationspreyonverydifferentspecies,presumablyinresponseto availability.Thisislikelytobufferimpactsofclimatechangeandchangesin marineecosystems.

•Fulmarsfrequentlyskipbreedinginpoorconditions;thismaybeadaptivein responsetoclimatechangeasitallowsadultstomaximiseconditionforgood breedingyears.

•Fulmarshaveshiftedtheirmigrationtimingandlayingdateinsome populations;thismayberelatedtoconditionsinbreedingandnon-breeding areasbuttheunderlyingreasonsarecurrentlyunknown.

3Band-rumpedStorm-petrel

(Hydrobatescastro)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Speciesisdeclininginmanyareas;rangewaslikelymuchlargerhistorically buthasbeengreatlyreducedbyintroducedpredators.Anyadditionalpressure fromclimatechangeislikelytoacceleratethesedeclines

•Band-rumpedstorm-petrelsrelyonwindconditionstosoaranduseaslittle energyaspossible.Changesinwindstrength,directionandpatternscould

• heavilyimpactenergyuseandmigrationpaths.

•Band-rumpedstorm-petrelshavehighbreedingsynchrony;themajorityof birdsinapopulationwilllaytheireggsinashortperiodoftime.Iftemporal shiftsinkeypreyavailabilityoccuritcouldhavesignificantimpactsonbreeding populations

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Specieshasveryhighfidelitytobreedingareas,andeventoindividual burrows.Unlikelytodisperseandcolonisenewareasreadilyinresponseto climatechange.

•Thereisverylimitedmixingbetweenpopulationsinstorm-petrels.Thiscan beadaptive(asitincreaseslikelihoodoflocaladaptation)ornon-adaptive(as immigrationtosupportpopulationsisunlikely).

4Leach’sStorm-petrel (Hydrobatesleucorhous)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (76%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(24%). Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts

attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope

•Leach’sstorm-petrelsinNorthAmericahavechangedtheirpreyspeciesand foragingstrategyinresponsetoshiftsinthemarineecosystempartiallydriven byclimatechange.

•HeatwavesinNorthAmericahaveimpactedstorm-petrelcoloniesand resultedinchangesindiet,lossofconditionandwrecks.

•Leach’sstorm-petrelreproductivesuccesshasbeenlinkedtoglobal temperature.Warmertemperaturesresultinhigherreproductivesuccess,up untilacertainthresholdafterwhichitdecreases.Themechanismisunknown.

1.2Sensitivity

•Specieshasalargepopulationandlargerangebutisrapidlydecliningacross itsrange.Theexactcauseisnotcertain,buttherearelikelyanumberof factors,includingbycatch,avianandmammalpredation,pollutionand disturbance.Anyadditionalpressurefromclimatechangeislikelytoaccelerate thesedeclines.

•Knowntowreckingreatnumbersinvariouspartsofitsrange,especially whenstrongprolongedoff-shorewindsoccurwhichcanblowpetrelsfarfrom theirusualmigrationroute.Changesinwindandstormpatternscould potentiallyhavesignificantimpacts.

•Hightemperaturesinotherpartsofthespecies’range,especiallyheatwaves,areassociatedwithlowerpreyavailability,lossofcondition,lower reproductiveoutputandsometimeswithdie-offs.Anincreaseintemperatureor heatwavesislikelytohaveasignificantimpactonbreedingcolonies.

•Leach’sstorm-petrelsrelyonwindconditionstosoaranduseaslittleenergy aspossible.Changesinwindstrength,directionandpatternscouldheavily impactenergyuseandmigrationpaths.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Leach’sstorm-petrelhasaflexiblemigrationstrategy,andchangesits migrationroute,stop-oversandwinteringareasbasedonconditions.Local changestomigrationroutesareunlikelytohaveamajorimpact.

•Leach’sstorm-petrelisknowntochangepreyspeciesandforagingareasin responsetochangesinconditions.Theyhaveaverylargeforagingrangeand localchangesinclimatearethereforelesslikelytohavealargeimpact.

•Analysisoflayingdateshasshownthat,regardlessofSSTandweather conditions,thereislittlevarianceinshearwaterphenology.Itisunlikelythey willadapttheirlayingdatetochangingconditions.

•Specieshasveryhighfidelitytobreedingareas.Unlikelytodisperseand colonisenewareasreadily.

•Thereisverylimitedmixingbetweenpopulationsinstorm-petrels.Thiscan beadaptive(asitincreaseslikelihoodoflocaladaptation)ornon-adaptive(as immigrationtosupportpopulationsisunlikely).

5EuropeanStorm-petrel

(Hydrobatespelagicus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (72%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(28%).

Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: High windsandstormsinthenonbreedingseasoncauseincreasedmortality,lowerbodycondition,andreduced breedingsuccess.Whileindividualextremeclimateeventsaredifficultto attributetoclimatechange,itislikelythatclimatechangeisdrivinganincrease intheirfrequencyand/orintensity.

NeutralImpact: Ashifttowardswarmer,drierandcalmerconditionshas resultedinlowerstormpetrelabundance.Themechanismisunknown,butlikely relatedtochangesinmarineecosystemandkeypreyavailability.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Studiesinotherpartsofthisspecies’rangehavefounditissensitivetohigh rainfallandlowtemperatures,whichcauseshighchickmortality.Ifclimate changecausesperiodsoflowtemperaturesandhigherrainfallduringthe breedingseason,thismayheavilyimpactjuvenilesurvival.

•Mortalityofbreedingstorm-petrelsissignificantlyincreasedduringsummers withahighincidenceofheavystorms,astheycreatedifficultforaging conditionsandlowerbodycondition.Projectedincreaseinthefrequencyof stormsmaythereforeheavilyimpactstorm-petrelpopulations.

•Europeanstorm-petrelsrelyonwindpatternstoflyandnavigate;athigh windspeedsstorm-petrelsarevulnerabletobeingstorm-driven.Higher incidenceofextremewindeventsislikelytohavesignificantimpactsonforaging abilityandmarinedistribution.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasepopulationextinctionrisk.

1.3Adaptivecapacity

•Analysisoflayingdateshasshownthat,regardlessofseatemperaturesand weatherconditions,thereislittlevarianceinstorm-petrelphenology.Itis unlikelytheywilladapttheirlayingdatetochangingconditions,whichcould makethemvulnerabletoclimatechange.However,additionalevidencehas foundthatchangesinmarinetemperaturedonotaffectbreedingsuccessfor storm-petrelsintheMediterranean.

•Inresponsetopoorbreedingconditions,Europeanstorm-petrelscanskip breedingevents.Thiscouldbufferthenegativeeffectsofclimatechange,as storm-petrelscouldmaintainbodyconditioneveninpooryearsbyskipping breeding.

•Specieshasveryhighfidelitytobreedingareas.Unlikelytodisperseand colonisenewareasreadily.However,thereisanecdotalevidencethatEuropean storm-petrelswillrecoloniseoldbreedingsitesifkeythreatsareremoved (e.g.predators).

•Europeanstorm-petrelshaveflexibleforagingbehaviourandpreyonawide varietyofspecies.Theyarelikelytotakeadvantageofalternativepreysources ifclimatechangeimpactsoneorafewpreyspecies.

•Thereisverylimitedmixingbetweenpopulationsinstorm-petrels.Thiscan beadaptive(asitincreaseslikelihoodoflocaladaptation)ornon-adaptive(as immigrationtosupportpopulationsisunlikely).

6ManxShearwater (Puffinuspuffinus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (66%ofcurrentrange)

Currentbreedingareathatis likelytoremainsuitable(34%)

Currentbreedingareathatis likelytobecomemoresuitable (0%)

1.1.2Currentimpacts attributedtoclimatechange: NegativeImpact: Reduced preyavailabilityduringthe breedingseasonhasledtolongerforagingtripsandlowerconditioninadults andchicks.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSea.

1.1.4ClimatechangeimpactsoutsideofEurope

•Manxshearwatersareknowntobesensitivetoclimatechangeinthetropics, particularlytowreckscausedbystorms,whicharebecomingmorecommondue tochangesintheElNiñocycle.

1.2Sensitivity

•Manxshearwaterburrowsarepronetoflooding;heavyrainfallduringthe incubationperiodcanresultinmanynestsbeinglost.Somepopulationsmay evenbeconstrainedbythenumberofnestsitesthatarepronetoflooding.An increaseinextremeprecipitationeventsduetoclimatechangeislikelytohave significantimpactsonshearwaterpopulations.

•Manxshearwaters,andshearwatersingeneral,relyonwindconditionsto soaranduseaslittleenergyaspossible.Changesinwindstrength,direction andpatternscouldheavilyimpactenergyuseandmigrationpaths.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasepopulationextinctionrisk.

1.3Adaptivecapacity

•Juvenilesoccasionallydispersetoothercolonies,butoncebreedingthe specieshasveryhighfidelity.Thereislimitedmixingbetweengroups,leading topopulationdivergence,andtheyareunlikelytodispersetoorfoundnew colonies.

•Despitethespecies’generallyhighsitefidelity,Manxshearwatershave colonisedpartsofNorthAmericainthelastcentury,indicatingthespeciescan successfullyestablishnewcolonies.Climatechangeispotentiallyacontributing factortothisshiftindistribution.However,thisisconsideredarelativelyrare event,anditseemsunlikelythespeciescanrapidlyshifttheirdistributionin responsetoclimatechange.

Potentialactionsinresponse toclimatechange:Petrels andShearwaters (Hydrobatidaeand Procellariidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)increasesforagingdifficultyand/ormortality

Summary: Invasivemammalsareamajorthreattomanyseabirdpopulations,andassuch thereisawell-establishedliteratureonmammalexclusion,managementand eradicationdetailingeffectivemethodsandcasestudies.However,therearemore limitedoptionswhenthemammalianpredatorinquestionisitselfaconservation target,orisnoteasilymanaged.Nevertheless,formanysituationsthereare several,well-researched,actionsavailablethatcanbenefitseabirdpopulations effectively.

Intervention EvidenceofEffectiveness

Provide supplementa ryfood duringthe breeding season

Trialledonmanyseabirdspecies.Verylimited trialsonpetrelsandshearwaters,andwith limitedsuccess.Itmaybepossibletofeeda smallnumberofchicksforalimitedamountof time,butfeedingadultssupplementaryfoodis likelyunfeasibleor,attheleast,extremely challenging.

3

Provide supplementa ryfood duringthe non-breeding season

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

NA NA NA

Rehabilitate sickor injuredbirds

Forothergroupsoflong-lived,largebirds, rehabilitationhasbeenshowntobeeffective (particularlyinraptors).However,examplesin seabirdsarescarceandtheoverall effectivenessformostspeciesisunknown.The fewexamplesthatexistforseabirdsshow mixedsuccessrates,butthereisatleastone exampleofsuccessfulmass-treatmentfollowing strandinginterns.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 2studiesintheevidencebasefocusonpetrelsandshearwaters,14 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof16studies.Ofthese10wereconsideredtohaveagoodsamplesize, and14hadaclearmetricforeffectiveness. Transparency(T): 16studiesincluded werepublishedandpeer-reviewed,0werefromthegreyliterature,and0were anecdotal.Ofthestudiesincluded,13hadapublishedmethodology,and4justified

theirrationale.

Rehabilitatesickorinjuredbirds

Relevance(R): 0studiesintheevidencebasefocusonpetrelsandshearwaters,3 onotherseabirdsand4onotherbirds. Strength(S): Theevidencebasewas comprisedof7studies.Ofthese4wereconsideredtohaveagoodsamplesize,and 1hadaclearmetricforeffectiveness. Transparency(T):7studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,5hadapublishedmethodology,and5justifiedtheir rationale.

2Impact:Reducedpreyavailabilityduringbreedingseason

Summary:

Severallocalactionsmayassistbreedingpopulationsonasmallscale,butdirect interventiononalargescaleislikelytobeextremelydifficult.Generalconservation actionstoprotectfishstocksandlocalmarineareasmaybethemosteffective method.Ifapopulationislikelytosuffermajorlosses,evenwithconservationhelp, thentranslocationscouldbeconsidered.

Intervention EvidenceofEffectiveness

Artificially incubateor hand-rear chicksto support population

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Several petrelandshearwaterspecieshavebeenhandrearedsuccessfully,buttypicallyinsmall numbers.

R S T

Makenew colonies more attractiveto encourage birdsto colonise

Trialledextensivelyacrossotherseabirds,with variablesuccess.However,inpetrelsand shearwaterstheuseofvocalisations,smells andsuitableburrowshavebeengenerally successfulinencouragingestablishment, especiallywhencombinedwithother conservationactions.Theeffectivenessofeach individualactionismixed,andvaries dependingonthespeciesandpopulationin question.

3 2 3

2 4 3

Provide supplementa ryfood duringthe breeding season

Trialledonmanyseabirdspecies.Verylimited trialsonpetrelsandshearwaters,andwith limitedsuccess.Itmaybepossibletofeeda smallnumberofchicksforalimitedamountof time,butfeedingadultssupplementaryfoodis likelyunfeasibleor,attheleast,extremely challenging.

Translocate the populationto amore suitable breeding area

Knowntobebeneficialinseveralseabird groups,andmultipletranslocationsofpetrels andshearwatershavebeencarriedout successfully.Thereisasubstantialbodyof workonmaximisingtranslocationsuccess,and encouragingestablishment.Notehowever translocationshavebeeninthecontextof islandrestorationandpredatorremoval,and (likemanyotheractions)havenotbeentrialled asaresponsetoclimatechange.

3 4 3

4 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 4studiesintheevidencebasefocusonpetrelsandshearwaters,36 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof40studies.Ofthese9wereconsideredtohaveagoodsamplesize, and19hadaclearmetricforeffectiveness. Transparency(T): 26studiesincluded werepublishedandpeer-reviewed,0werefromthegreyliterature,and0were anecdotal.Ofthestudiesincluded,17hadapublishedmethodology,and4justified theirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 9studiesintheevidencebasefocusonpetrelsandshearwaters,29 onotherseabirdsand6onotherbirds. Strength(S): Theevidencebasewas comprisedof44studies.Ofthese31wereconsideredtohaveagoodsamplesize, and18hadaclearmetricforeffectiveness. Transparency(T): 44studiesincluded werepublishedandpeer-reviewed,ofwhich1wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies

included,30hadapublishedmethodology,and22justifiedtheirrationale.

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 2studiesintheevidencebasefocusonpetrelsandshearwaters,14 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof16studies.Ofthese10wereconsideredtohaveagoodsamplesize, and14hadaclearmetricforeffectiveness. Transparency(T): 16studiesincluded werepublishedandpeer-reviewed,0werefromthegreyliterature,and0were anecdotal.Ofthestudiesincluded,13hadapublishedmethodology,and4justified theirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 7studiesintheevidencebasefocusonpetrelsandshearwaters,8 onotherseabirdsand0onotherbirds. Strength(S): Theevidencebasewas comprisedof15studies.Ofthese13wereconsideredtohaveagoodsamplesize, and9hadaclearmetricforeffectiveness. Transparency(T): 14studiesincluded werepublishedandpeer-reviewed,ofwhich1wereliteraturereviewsormetaanalyses,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,11hadapublishedmethodology,and9justifiedtheirrationale.

1GreatSkua

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (78%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(19%).

Currentbreedingareathatis likelytobecomemoresuitable (3%).

1.1.2Currentimpacts attributedtoclimatechange:

(Catharactaskua)

NegativeImpact: Hotter summersresultinincreased heatstressinadultsandchicks.Adultsmorefrequentlyleavenestsunattended tothermoregulate,whichexacerbateschickheatstress.

NegativeImpact: Inhottersummers,adultsmorefrequentlyleavenests unattendedduetopreyshortagesandtothermoregulate,whichresultsinhigher chickmortalityduetopredation.

NegativeImpact: Changesinpreyavailabilityduringthebreedingseason haveledtodecreasedfledglingsuccess.

PositiveImpact: Changesinpreyavailabilityhaveledtoincreased populationsize.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.2Sensitivity

•Skuasaresensitivetohightemperatures,andtheirsouthernrangelimitis likelydefinedbymaximumtemperature.Climatechangeislikelytomakethe southernmostmostpopulationsunviableinthefuture.

•Parasitismandpredationofseabirdsisanimportantpartofskuadiets,and climatechangemayheavilyimpacttheirpreyspecies.Inaddition,theyoften cannibalisetheirneighbours,andthisbehaviourmayincreaseasalternative preybecomesscarce.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•Greatskuashaveveryvarieddietsandforagingstrategiesandwillchange theirdietdependingonavailability.Thisflexibilitymaymeanskuascanmitigate theimpactoflosingkeypreyspecies.

•Greatskuasareabletoestablishandcolonisenewareas,andhavealready donesoatthenorthernedgeoftheirrange.Theymaybeabletoshifttheir rangeinresponsetoclimatechange.

2Long-tailedJaeger

(Stercorariuslongicaudus)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (95%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(3%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts attributedtoclimatechange: NegativeImpact: Southernpopulationsare becominglesspopulousorgoingextinctincorrelationwithrisingtemperatures. Exactmechanismunknown,probablyrelatedtopreyavailabilityorheatstress.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyassessmentwascarriedoutforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope:

Long-tailedjaegershavebeenheavilyaffectedbyclimatechangeinGreenland, inparticularduetolackofpreyandincreasedpredationduetootherspecies prey-switching.

1.2Sensitivity

•Duringthebreedingseasonjaegersareheavilyreliantonafewspeciesof lemmingsandvoles,andanyimpacttothesespeciesislikelytoheavilyaffect skuabreedingsuccess.

•Long-tailedjaegerpopulationsarehighlyconcentratedinthenon-breeding season.>50%ofglobalpopulationcongregateduringmigrationinarelatively smallareaofthecentralAtlantic.Anynegativechangetothisareaislikelyto havesevereconsequencesonskuapopulations.

•Long-tailedjaegerchicksarehighlyvulnerabletopredationbyArcticandred foxes(leadingtoupto100%mortalityinsomeyears).Anychangesinfox abundance(eithernegativeorpositive)mayhavesevereimpactsonlong-tailed jaegerpopulations.

1.3Adaptivecapacity

•Jaegersareverysite-tenacioussoanyresponsetochangeislikelytobevery slow,andrangeshiftsintheshorttermareveryunlikely.

•Long-tailedjaegerswillskipbreedinginyearswithpoorpreyavailability, whichmaybeadaptiveandmaximisesbreedingoutputovertimeandhelpthem copewithclimatechange.Long-tailedjaegersarelong-livedandseveralyears ofbreedingfailureorskippedbreedingmaynothavealong-termimpactonthe populationifpopulationsareabletobreedsuccessfullyingoodyears.

3ArcticJaeger (Stercorariusparasiticus

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (81%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(13%).

Currentbreedingareathatis likelytobecomemoresuitable (6%).

1.1.2Currentimpacts

attributedtoclimatechange:

NegativeImpact: Changes inpreyavailabilityhaveledto declinesinkeyseabirdspeciesthatArcticjaegersparasitise,thusleadingto populationdeclines.

NegativeImpact: Increasedcompetitionandpredationfromgreatskuas, duetoanincreasingpopulationsizeandpreyswapping.

1.1.3Predictedchangesinkeypreyspecies:

Nokeypreyassessmentwascarriedoutforthisspecies.

1.2Sensitivity

•WhileArcticjaegersparasitiseanumberofseabirdspecies,thebreeding successofmanypopulationsiscloselylinkedtheabundanceofkeyfishspecies. SeveredecreasesinArcticjaegerpopulationshavebeenlinkedtopreydeclines,

andchangesinfishdistributionsduetoclimatechangearelikelytohaveheavy impactsonpopulations.

•Arcticjaegerpopulationsaresensitivetopredation,andseveralcolonies havedeclinedduetoincreasedpredationbygreatskuasandredfoxes.Changes inpredatorabundanceorrangeduetoclimatechange(e.g.theexpansionof redfoxesinScandinavia)arelikelytohaveimpactsonjaegerpopulations.In addition,jaegerskuasuseco-operativedefencewhichbecomeslesseffective insmallerpopulations.Thismayresultinafeedbackloopwheregreater predationdecreasespopulationsize,increasingvulnerabilitytopredation.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•InmostpartsoftheirrangeArcticjaegersareanumerous,long-lived, ecologicallyflexiblespecies,soarelikelytoberobusttochange.

•Insomeareas,particularlynearmajorseabirdcolonies,Arcticjaegershave aquiterestricteddietbasedonkleptoparasitism.Howeverinmanyareasacross theirrangetheyhaveaveryvarieddiet,andwillfeedonthemostavailable food,includingbirds,eggs,rodents,insects,fish,berriesandcarrion.This plasticityislikelytoincreaseresiliencetoclimatechange,butvariablyacross populations.

•ThereisconsiderablevariationinmigrationrouteandwinteringsitesinArctic jaegers,evenwithinasinglecolony.Thiswilllikelyprovideabuffertoclimate change,aschangestoanyonewinteringsitearelesslikelytoaffectthe populationasawhole.

Potentialactionsinresponse toclimatechange:Skuas (Stercorariidae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Increaseinavianpredation

Summary: Thereareanumberofavailablelocalactionstopreventormitigateavianpredation, someofwhichhavebeentrialledextensivelyinseabirdswithpositiveresults.Other actionsarepoorlyunderstood,butcouldbeconsideredaftermoreinvestigation.If predationissevere,andislikelytoincreaseduetoclimatechangeorspeciesrange shifts,thentranslocationcouldbeconsidered.

Intervention EvidenceofEffectiveness R S T

Artificial

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds. NA NA NA Manage/

Hasbeentrialledwithsomesuccessonseveral seabirdgroups,thoughhasneverbeentrialled forskuaconservation.Oftencarriedoutaspart ofasuiteofconservationactions,sodifficultto assesshoweffectivemanagementis.

Physically protectnests withbarriers orenclosures

Hasbeentrialledonmanyseabirdgroups, oftenwithnotablesuccess.Currentlyno reportsonitseffectivenessforskua conservation.Arelativelyeasy,inexpensive method,butdependentonbeingableto accessnest-sitesandeffectivelyprotect them.Assomeskuasnestinverylow densitiesacrosslargeareasoftundra,its practicalitymaybequestionable.

Reduce predationby translocating predators

Fewtrialsonseabirds,andnoneforskua conservation.Existingevidencesuggeststhis actioncanbebeneficialandreduceegg/chick predation,andcouldbeaviableactionif otherformsofpredatormanagementarenot viable.

2 4 4

Repel predators with acoustic, chemicalor visual deterrents

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

NA NA NA Use supplementa ryfeedingto reduce predation

Veryfewtrialsonseabirds,andnoneforskua conservation.Likelytobeverylabour intensiveanddifficultgiventheremoteand inaccessiblebreedingcoloniesofmanyskuas. Moreworkisneededtoexamineaction’s effectivenessonseabirds.

1 4 3

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Manage/eradicateavianpredators

Relevance(R): 0studiesintheevidencebasefocusonskuas,14onotherseabirds

and2onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese15wereconsideredtohaveagoodsamplesize,and5hadaclear metricforeffectiveness. Transparency(T): 16studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,9hadapublished methodology,and11justifiedtheirrationale.

Physicallyprotectnestswithbarriersorenclosures

Relevance(R): 0studiesintheevidencebasefocusonskuas,12onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof18 studies.Ofthese16wereconsideredtohaveagoodsamplesize,and12hada clearmetricforeffectiveness. Transparency(T): 17studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,11hadapublishedmethodology,and12justifiedtheir rationale.

Reducepredationbytranslocatingpredators

Relevance(R):0studiesintheevidencebasefocusonskuas,2onotherseabirds and2onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and3hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and3justifiedtheirrationale.

Usesupplementaryfeedingtoreducepredation

Relevance(R): 0studiesintheevidencebasefocusonskuas,1onotherseabirds and3onotherbirds. Strength(S): Theevidencebasewascomprisedof4studies. Ofthese4wereconsideredtohaveagoodsamplesize,and4hadaclearmetricfor effectiveness. Transparency(T): 4studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and4justifiedtheirrationale.

2Impact:Increaseincompetition

Summary:

Localactionstopreventormitigatetheeffectsofcompetitionarenotwell understood,andtheireffectivenessisunclear.Inmanycontextstheyarelikelyto bedifficultorimpossibletocarryoutonlargepopulations.Supportingpopulations moregenerally(increasingadultsurvival,limitingchickmortality)maybeamore appropriatestrategy.

Protectnest sitesfrom competitors

Reduce competitionby removing competitor species

Use supplementary feedingto reduce competition

Onlytrialledononepopulationofpetrels (withlimitedsuccess),allotherexamples focusonnon-seabirdspecies(manyofwhich weresuccessful).Moreworkisneededto examineaction’seffectivenessonseabirds.

Trialledextensivelyonterns,butlimitedtrials forotherseabirdgroups,andnoneforskua conservation.Successismixed,sometrials havefoundbenefits,butmanyhavereported noeffectorevennegativeconsequencesof thisaction.

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

1

2 3 3

NA NA NA

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Protectnestsitesfromcompetitors

Relevance(R): 0studiesintheevidencebasefocusonskuas,2onotherseabirds and5onotherbirds. Strength(S): Theevidencebasewascomprisedof7studies. Ofthese5wereconsideredtohaveagoodsamplesize,and2hadaclearmetric foreffectiveness.Transparency(T): 6studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,3hadapublishedmethodology,and4justifiedtheirrationale.

Reducecompetitionbyremovingcompetitorspecies

Relevance(R): 0studiesintheevidencebasefocusonskuas,12onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof12 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and5hadaclear metricforeffectiveness. Transparency(T): 12studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthe studiesincluded,8hadapublishedmethodology,and7justifiedtheirrationale.

3Impact:Increasedthermalstress

Summary:

Therearecurrentlynowell-researchedmethodstodirectlyassistseabirdswith thermalstress,andmoreinformationisneededonhowthermalstresscanimpact seabirdsandhowlocalconservationactioncanmitigatetheseimpacts.Ifthermal stressbecomessocommonorextremethatitthreatenstheviabilityofa population,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention

Makenew

Hasbeentriedextensivelyonmany differentseabirdgroupswithfrequent, thoughnotuniversal,success.However, currentlytherearenoreportsonthis action’seffectivenessforskuas.

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds. NA NA NA

Verylimitednumberoftrialsinseabirds, somelimitedbenefitsfoundforproviding additionalshelterfromthesunfor cormorants.Moreworkisneededto examineaction’seffectivenessonseabirds.

Knowntobebeneficialinsomeseabird groups,butnorecordedtrialsinskuas. Skuastendtohaveextremelyhigh territorialityandsite-fidelityso translocationofadultsislikelytobe extremelydifficult,ifnotimpossible. Whethertranslocationisplausible,or beneficial,toskuasiscurrentlyunknown andfurtherresearchisneeded.

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusonskuas,38onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(heatwaves)

Relevance(R): 0studiesintheevidencebasefocusonskuas,1onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof1study. Ofthese1wasconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T): 1studyincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,0hadapublishedmethodology,and1justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 0studiesintheevidencebasefocusonskuas,15onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

4Impact:Reducedpreyavailabilityduringbreedingseason

Summary:

Severallocalactionsmayassistbreedingpopulationsonasmallscale,butdirect interventiononalargescaleislikelytobeextremelydifficult.Generalconservation actionstoprotectfishstocksandlocalmarineareasmaybethemosteffective method.Ifapopulationislikelytosuffermajorlosses,evenwithconservationhelp, thentranslocationscouldbeconsidered.

Intervention EvidenceofEffectiveness

Artificially incubateor hand-rear chicksto support population

Makenew colonies more attractiveto encourage birdsto colonise

Provide supplementa ryfood duringthe breeding season

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Toour knowledge,therearenoexamplesofskuas beinghand-rearedsuccessfully.

Hasbeentriedextensivelyonmanydifferent seabirdgroupswithfrequent,thoughnot universal,success.However,currentlythere arenoreportsonthisaction’seffectivenessfor skuas.

R S T

2 2 1

Translocate the populationto amore suitable breeding area

Trialledonseveralseabirdspecies,withsome, thoughnotuniversal,success.Trialledononly onepopulationofskuas,whichfoundlittle benefit.Typicallyverylabourintensiveand difficultgiventheremoteandinaccessible breedingcoloniesofmanyskuas.Probablyonly plausibleforsmallpopulations.

Knowntobebeneficialinsomeseabirdgroups, butnorecordedtrialsinskuas.Skuastendto haveextremelyhighterritorialityandsitefidelitysotranslocationofadultsislikelytobe extremelydifficult,ifnotimpossible.Whether translocationisplausible,orbeneficial,to skuasiscurrentlyunknownandfurther researchisneeded.

2 4 3

3 4 3

2 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence.

R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 0studiesintheevidencebasefocusonskuas,40onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T):26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 0studiesintheevidencebasefocusonskuas,38onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 2studiesintheevidencebasefocusonskuas,14onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 0studiesintheevidencebasefocusonskuas,15onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

1ArcticTern (Sternaparadisaea)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (87%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(10%).

Currentbreedingareathatis likelytobecomemoresuitable (3%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: Changes inpreyavailabilityduringthe breedingseasonhaveledtopopulationdeclines(debated).

NegativeImpact: Changesinpreyavailabilityduringthebreedingseason haveledtopopulationdeclines.

NeutralImpact: Arcticternsarearrivingfrommigrationandbreeding earlier.

NeutralImpact: JuvenileArcticternshavebeguntodispersefurther, distancehasincreasedincorrelationwithwarmerwinters.Mechanismunknown, butlikelymediatedthroughpreyavailability.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheIrishSeaand aroundNorthDenmark.

1.2Sensitivity

•AroundtheNorthSeaArcticternsareverydependentonsandeelsandhighly sensitivetopreydepletion.Lackofsandeelscancausemassbreedingfailures, andseveralhavebeenobservedinrecentyears.Ifclimatechangecontributes tothedeclineofsandeelsthisislikelytohavesevereconsequencesontern populations.

•Ternproductivitydecreasesasseasurfacetemperaturegetshigher,most likelyduetopreyavailability.Whilethemechanismisunclear,projected increasesinseatemperaturearelikelytonegativelyimpactternpopulations.

•Arcticternsareprimarilysurfacefeeders.Ifclimatechangeresultsin prolongedstormyweather,orextendedheatwavesdrivepreyspeciesinto deeperwater,thenitwouldlikelyresultinArcticternsstrugglingtoforage effectively.

•Thisspecieshasalonggenerationlength(>10years),whichmayslow recoveryfromsevereimpactsandincreasespopulationextinctionrisk.

1.3Adaptivecapacity

•DispersalbetweencoloniesinDenmarkhassteadilyincreasedoverthelast 70years,incorrelationwithchangesinclimate(winterNAO).Theexact mechanismisunknown,buthighdispersaltypicallymeansmoregeneticflow andthereforeresilienceinthepopulation.

•Arcticternscanskipbreedingwhenconditionsareparticularlypoor.Thisis likelytobeadaptiveinthefaceofclimatechangeasitconservesresourcesin pooryearsandmaximisesbreedingsuccessingoodyears

•Arcticternpopulationshaveawidevariationinmigrationstrategyinterms ofrouteandtiming.Thisislikelytomakepopulationsmoreresilientasimpacts toonepartofthemigrationrouteareunlikelytohavemajorimpactsonthe populationasawhole.

•Arcticternslikelyhavehighsitefidelity,particularlyatstablecolonies.There arefewexamplesofArcticternsestablishingnewcoloniesspontaneously.They areunlikelytoshifttheirrangequicklyinresponsetoclimatechange.

2LittleTern (Sternulaalbifrons)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (3%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(57%).

Currentbreedingareathatis likelytobecomemoresuitable (59%).

1.1.2Currentimpacts attributedtoclimatechange:

NegativeImpact: Little ternnestsarefrequently washedawaybytidalsurges,sucheventsarebecomingmorefrequentor extensiveduetorisingsealevels.

NegativeImpact: Asseatemperaturehasincreasedovertime,tern productivityhasdecreased.Mechanismunknown,butlikelymediatedthrough preyavailability.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceinsouthernPortugal, alongthesoutherncoastofEngland,thecoastsofBelgiumandtheNetherlands andaroundNorthDenmark.

1.2Sensitivity

•Littleternshaveavarieddiet,butmanycoloniesrelyononeorafewprey species.Sensitivitytochangesinpreyislikelytovaryacrossitsrange.Insome populations(suchasinAlgarve,Portugal),warmertemperatureshavebeen linkedtolowerkeypreyavailabilityandlowerbreedingsuccess,thoughthere hasbeennolong-termtrendobservedovertime.

•Coastalpopulationsbreedcommonlyonflatbeaches,whichareproneto floodingduetostorms,tidalsurgesorsealevelrise.Ariseinextremeweather eventswouldlikelyimpactbreedingsuccessoflittleterns.

•Littleternsareprimarilysurfacefeedersandhavealimitedforagingrange duringthebreedingseason.Thisincreasestheirsensitivitytochangesinprey availability,andtheywouldlikelybeheavilyimpactedifclimatechangeresults inprolongedstormyweather,orextendedheatwavesdrivepreyspeciesinto deeperwater.

•Littleternsfacehighlevelsofpredationthreat,notablyintheBaltic,and severaloftheirkeypredators(e.g.minksandfoxes)arebecomingmore abundantandspreading,inpartduetoclimatechange.Sofarthishasnot heavilyimpactedlittleternpopulations,butcontinuedclimatechangemay resultindeclinesduetopredation.

1.3Adaptivecapacity

•Littleternscanchangetheirphenologybasedonclimateandweather. PopulationsinFinlandchangetheirmigrationtiminginresponsetowinterand springclimate,andtheirlayingdateinresponsetolocalweatherconditions. Thismayallowlittleternstorespondtochangingclimateandmitigateimpacts leadinguptothebreedingseason.

•Littleternsoftendisplaylowsitefidelityandwillchangebreedingsitefrom yeartoyear,especiallyinresponsetodisturbance.Thisislikelytobeadaptive intermsofclimatechange,asitseemshighlylikelylittleternswillredistribute tomoresuitableareasifavailable.

3RoseateTern (Sternadougallii)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (100%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(0%). Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies:

KeypreyspeciesarelikelytodeclineinabundanceintheEnglishChannel.

1.2Sensitivity

•RoseateternshaveasmallrangeinEurope,andmanypopulationshave historicallygoneextinctduetopersecution,disturbance,orextremeclimate events.Increasedpressurefromclimatechangeislikelytoincreaseriskof declinesorlocalextinction.

•Roseateternsareprimarilysurfacefeeders.Ifclimatechangeresultsin prolongedstormyweather,orextendedheatwavesdrivepreyspeciesinto

deeperwater,thenitwouldlikelyresultinternsstrugglingtoforageeffectively.

•Roseateternsarespecialistforagers,andpreyonrelativelyfewspecies comparedtootherterns.Theymaybeparticularlysensitivetochangesinkey preyspecies.

•ManyEuropeanRoseateternswinteroffthecoastofwestAfrica,whereprey availabilityislinkedtokeyupwellingsystems.Thereisevidencethatthese upwellingsmaychangeorbedisruptedbyclimatechange.Ifthishappensitis likelytohavesevereconsequencesonternmortality,conditionduringthe breedingseasonandtimingofmigration.

•Roseateternsonlynestaroundotherterns,inparticularcommonterns,and relyonthemforprotectionfrommoreaggressivespecies.Anyimpactstothese otherspeciesislikelytohavenegativeconsequencesforroseateterns.

1.3Adaptivecapacity

•TheeasternAtlanticroseateternpopulationisthoughttobeaclosed population,soisunlikelytobesupplementedbyindividualsfromothercolonies. Geneticdiversityisunlikelytoincreaseandmayresultinbottlenecks,possibly hamperingrecoveryifclimatechangeresultsinpopulationdecline.

4SandwichTern (Thalasseussandvicensis

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (72%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(26%).

Currentbreedingareathatis likelytobecomemoresuitable (2%).

1.1.2Currentimpacts attributedtoclimatechange:

NeutralImpact: Sandwich ternsarechangingtheir migrationtimingandarrivingearliertobreedingsites.

NeutralImpact: Sandwichternsarechangingtheirmigrationtiming,both migrationandbreedingeventsareoccurringlater,makingthebreedingseason shorter.

1.1.3Predictedchangesinkeypreyspecies:

Keypreyspeciesarelikelytodeclineinabundanceonthesoutherncoastof England,aroundtheBrittanycoast,aroundNorthDenmarkandaroundthe southcoastofIreland.

1.2Sensitivity

•AsSandwichternsnestonlow-lyinggroundclosetothewater’sedge,their nestsarevulnerabletotidalinundation.Sofartherearenostudiesonwhether climatechangeisaffectingbreedingpopulationsthroughincreasedflooding,but predictionsofincreasedstorminessandsea-levelriseunderclimatechange scenariosmayleadtomorenestingpopulationsbeinglost.

1.3Adaptivecapacity

•Sandwichternshaveflexiblemigrationandlayingphenology,andseveral populationshavealreadychangedthetimingofmigrationandbreedingin responsetoclimatechange.However,whetherthisisadaptiveornotis currentlyunknown.

•Sandwichternsoftendisplaylowsitefidelityandwillchangebreedingsite fromyeartoyearinresponsetochangingconditionsordisturbance.Thisis likelytobeadaptiveintermsofclimatechange,asitseemshighlylikely Sandwichternswillredistributetomoresuitableareasifavailable.

5CaspianTern (Hydroprognecaspia)

1.1Evidencefor exposure

1.1.1Potentialchangesin breedinghabitatsuitability (by2100):

Currentbreedingareathatis likelytobecomelesssuitable (97%ofcurrentrange).

Currentbreedingareathatis likelytoremainsuitable(3%). Currentbreedingareathatis likelytobecomemoresuitable (0%).

1.1.2Currentimpacts attributedtoclimatechange: Wedidnotidentifyanycurrent impactsofclimatechangefor thisspecies.

1.1.3Predictedchangesinkeypreyspecies: Nokeypreyspeciesarepredictedtodeclineforthisspecies.

1.1.4ClimatechangeimpactsoutsideofEurope

•CaspianternsinNorthAmericahavebeennegativelyaffectedbyheatwaves, warmingseas,severestorms,andincreasedfrequencyofflooding,allofwhich arelinkedtoclimatechange.

1.2Sensitivity

•Caspianternchicksaresensitivetoheatwaves,andparticularlyhotsummers intheUShaveresultedinmassmortality.Heatwavesarelikelytobecomemore frequentandextremeduetoclimatechange,whichwilllikelynegativelyimpact Caspianterns.

•CaspianternsarevulnerabletopredationbyAmericanmink,whichare increasinginsomelocationsinpartduetoclimatechange.Noeffecton populationshasbeenobservedsofar,butclimatechangemaycontributeto additionalpredationpressure.

•CaspianternsinEuropetypicallynestonlow-lyingbeaches,makingthem sensitivetofloodingandtidalsurges.Extremeweathereventsareprojectedto becomemorefrequentinmanyareas,andthereforemaylowerternbreeding success.

•Caspianternsareprimarilysurfacefeeders.Ifclimatechangeresultsin prolongedstormyweather,orextendedheatwavesdrivepreyspeciesinto deeperwater,thenitwouldlikelyresultinCaspianternsstrugglingtoforage effectively.

•Caspianternstypicallyonlynestonrockysubstrateswithverylittle vegetation.Additionalgrowthcancausethemtoabandonnestingsites.Thisis aparticularlyanissueintheBalticduetohighlevelsofnutrientsonislands,and islikelytobeexacerbatedbyclimatechange.

1.3Adaptivecapacity

•Caspianternsareknowntoabandonandre-locatecoloniesfollowingchanges inenvironmentalconditionsordisturbance.Thisislikelytobeadaptiveinterms ofclimatechange,asitseemshighlylikelyternswillredistributetomore suitableareasifavailable.

Potentialactionsinresponseto climatechange:Terns(Laridae)

Inthissectionwelistandassesspossiblelocalconservationactionsthatcouldbe carriedoutinresponsetoidentifiedclimatechangeimpacts.Thissectionisnot groupedbyspecies,butbyidentifiedimpacts.Ifanimpactoractionisspecificto oneorafewspecies,thisinformationisincludedintheactionsummaryorinthe footnotes.Effectiveness,relevance,strengthandtransparencyscoresarebasedon theavailableevidencewecollated(seeAppendix2),andthereforeallstatements regardinglimitedoralackofevidencerelatetothecollatedevidencebase,and doesnotinferthatnosuchstudiesexist.

1Impact:Reducedpreyavailabilityduringbreedingseason Summary: Severallocalactionsmayassistbreedingpopulationsonasmallscale,butdirect interventiononalargescaleislikelytobeextremelydifficult.Generalconservation actionstoprotectfishstocksandlocalmarineareasmaybethemosteffective method.Ifapopulationislikelytosuffermajorlosses,evenwithconservationhelp, thentranslocationscouldbeconsidered.

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Noexamples ofhand-rearingternsarecurrentlyavailable, butitisunlikelytobeaviableoption.

Manyspeciesofternhavebeensuccessfully relocatedusingavarietyoftechniquestomake newareasmoreattractive,inparticular vocalisationsandmodificationofhabitat.While noteveryattemptedrelocationhasbeen successful,therearenumerousnotable successes,includingsuccessfulrelocationof largepopulationscontainingthousandsof individuals.

Provide supplementa ryfood duringthe breeding season

Trialledonmanyseabirdspecies,withmixed success.Few,ifany,successfulexamplesfor terns,thoughsomesupplementalfeedinghas beenattemptedonaverylocalscale. Typicallyverylabourintensiveanddifficult, especiallyasmanyternspeciesstrongly preferlivingpreyandareunlikelytotake deadprey.Unlikelytobeeffectiveformany terns,oronlyplausibleforsmallpopulations.

Translocate the populationto amore suitable breeding area

Knowntobebeneficialinotherseabird groups,butfewifanyexamplesinterns. Attemptstomovepopulationshavetypically usedattractantstoencouragemovement, ratherthanmanualtranslocation.Ifthetarget specieshashighsitefidelity,manual translocationmaybeappropriatebutlittleis knownaboutmethodsandeffectivenessof terntranslocation.

2 4 3

2 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details:

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R):0studiesintheevidencebasefocusonterns,40onotherseabirds and0onotherbirds.Strength(S):Theevidencebasewascomprisedof40studies. Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclearmetric foreffectiveness.Transparency(T):26studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 22studiesintheevidencebasefocusonterns,16onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had

apublishedmethodology,and22justifiedtheirrationale.

Providesupplementaryfoodduringthebreedingseason

Relevance(R): 0studiesintheevidencebasefocusonterns,16onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof16 studies.Ofthese10wereconsideredtohaveagoodsamplesize,and14hada clearmetricforeffectiveness. Transparency(T): 16studiesincludedwere publishedandpeer-reviewed,0werefromthegreyliterature,and0wereanecdotal. Ofthestudiesincluded,13hadapublishedmethodology,and4justifiedtheir rationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R): 0studiesintheevidencebasefocusonterns,15onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof15 studies.Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclear metricforeffectiveness. Transparency(T): 14studiesincludedwerepublishedand peer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthe greyliterature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

2Impact:Increasedfrequency/severityofstorms(includingwind, rainandwaveaction)causesnestdestruction

Summary:

Whilethereareseverallocalactionsthatmaypreventormitigatelocalnest destruction,theyhavenotbeentrialledwidelyandwide-spreadevidencetosupport theiruseiscurrentlylacking.Ifchangesinextremeweatherthreatenstheviability ofapopulation,thenseveralactionsareavailabletoencouragetranslocationof populationstosaferareas.

Intervention EvidenceofEffectiveness

Alterhabitat toencourage birdstoleave anarea

Therearelimitedtrialsofthisaction,however thereareseveralsuccessfulexamplesof modifyinghabitattoencourageternstoleave, typicallybyencouragingvegetationtoovergrow nestingareas.Therearecurrentlynoavailable examplesinotherseabirds.

R S T

Artificially incubateor hand-rear chicksto support population

Install barriersto prevent flooding

Knowntobeeffectiveforsomeseabirds, thoughlabourintensiveandusuallyonly appropriateforsmallpopulations.Noexamples ofhand-rearingternsarecurrentlyavailable,it isunlikelytobeaviableoption,butmore researchisneededtoverifythis.

Thisisahypotheticalaction.Wefoundno publishedstudiesassessingthisaction’s effectivenessforseabirds.

Makenew colonies more attractiveto encourage birdsto colonise

Manyspeciesofternhavebeensuccessfully relocatedusingavarietyoftechniquestomake newareasmoreattractive,inparticular vocalisationsandmodificationofhabitat.While noteveryattemptedrelocationhasbeen successful,therearenumerousnotable successes,includingsuccessfulrelocationof largepopulationscontainingthousandsof individuals.

NA NA NA

4 4 3

Manually relocate nests

Thereisnopublishedevidenceregardingthis action’seffectiveness.However,first-hand accountsfrompractitionershavereportedthat manuallymovingnestshasbeentrialled,and withsomesuccess.Likelytoonlybeviablefor afewnestsattheedgeofcolonies,aslarger interventionsarelaborious,causemass disturbance,andmayresultinterns abandoningnests.

NA NA NA

Provide additional shelteror protection from extreme weather (flooding)

Therehavebeensomeattemptstoprovide shelterforternpopulationstoprotectnests fromflooding,howevernonesofarhaveshown anysignificantbenefit.Novelmethodsmay providemoreprotection,butthisrequires furtherresearch.

Provide artificial nesting sites

Repair/ support neststo support breeding

Triedextensivelyonmanyseabirdspecieswith significantbenefittomanyspecies.Artificial nestingsiteshavebeensuccessfullyusedto supportavarietyofternspecies,includingthe useofartificialislands,floatingraftsandnestboxes.

Thereislimitedevidencetosupportthisaction, asfewtrialshavebeencarriedoutonany seabirdspecies,andthosethatexistareona verylocalscale.Noattemptshavebeenmadeon terns.Moreresearchneededtodetermine effectivenessofthisaction.

Translocate the population toamore suitable breeding area

Knowntobebeneficialinotherseabirdgroups, butfewifanyexamplesinterns.Attemptsto movepopulationshavetypicallyusedattractants toencouragemovement,ratherthanmanual translocation.Ifthetargetspecieshashighsite fidelity,manualtranslocationmaybeappropriate butlittleisknownaboutmethodsand effectivenessofterntranslocation.

4 4 4

Green =Likelytobebeneficial. Red =Unlikelytobebeneficial,mayhavenegativeimpact. Orange =contradictingoruncertainevidence. Grey =Limitedevidence. R =relevancerating. S =strengthrating. T =transparencyrating.Allratingsonascaleof1to5, where5isthehighest.

Details: Alterhabitattoencouragebirdstoleaveanarea

Relevance(R): 2studiesintheevidencebasefocusonterns,0onotherseabirds and0onotherbirds.Strength(S): Theevidencebasewascomprisedof2studies. Ofthese2wereconsideredtohaveagoodsamplesize,and0hadaclearmetricfor effectiveness. Transparency(T): 2studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,2hadapublishedmethodology,and1justifiedtheirrationale.

Artificiallyincubateorhand-rearchickstosupportpopulation

Relevance(R): 0studiesintheevidencebasefocusonterns,40onotherseabirds and0onotherbirds. Strength(S): Theevidencebasewascomprisedof40 studies.Ofthese9wereconsideredtohaveagoodsamplesize,and19hadaclear metricforeffectiveness. Transparency(T): 26studiesincludedwerepublishedand peer-reviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies

included,17hadapublishedmethodology,and4justifiedtheirrationale.

Makenewcoloniesmoreattractivetoencouragebirdstocolonise

Relevance(R): 22studiesintheevidencebasefocusonterns,16onotherseabirds and6onotherbirds. Strength(S): Theevidencebasewascomprisedof44 studies.Ofthese31wereconsideredtohaveagoodsamplesize,and18hada clearmetricforeffectiveness. Transparency(T): 44studiesincludedwere publishedandpeer-reviewed,ofwhich1wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,30had apublishedmethodology,and22justifiedtheirrationale.

Provideadditionalshelterorprotectionfromextremeweather(flooding)

Relevance(R): 1studyintheevidencebasefocussesonterns,0onotherseabirds and2onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and2hadaclearmetricfor effectiveness. Transparency(T): 3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,3hadapublishedmethodology,and3justifiedtheirrationale.

Provideartificialnestingsites

Relevance(R): 17studiesintheevidencebasefocusonterns,35onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof54 studies.Ofthese50wereconsideredtohaveagoodsamplesize,and33hada clearmetricforeffectiveness. Transparency(T): 53studiesincludedwere publishedandpeer-reviewed,ofwhich2wereliteraturereviewsormeta-analyses,0 werefromthegreyliterature,and0wereanecdotal.Ofthestudiesincluded,33had apublishedmethodology,and27justifiedtheirrationale.

Repair/supportneststosupportbreeding

Relevance(R): 1studyintheevidencebasefocussesonterns,1onotherseabirds and1onotherbirds. Strength(S): Theevidencebasewascomprisedof3studies. Ofthese1wasconsideredtohaveagoodsamplesize,and1hadaclearmetricfor effectiveness. Transparency(T): 3studiesincludedwerepublishedandpeerreviewed,0werefromthegreyliterature,and0wereanecdotal.Ofthestudies included,1hadapublishedmethodology,and3justifiedtheirrationale.

Translocatethepopulationtoamoresuitablebreedingarea

Relevance(R):0studiesintheevidencebasefocusonterns,15onotherseabirds and0onotherbirds.Strength(S):Theevidencebasewascomprisedof15studies. Ofthese13wereconsideredtohaveagoodsamplesize,and9hadaclearmetric foreffectiveness.Transparency(T):14studiesincludedwerepublishedandpeerreviewed,ofwhich1wereliteraturereviewsormeta-analyses,0werefromthegrey literature,and0wereanecdotal.Ofthestudiesincluded,11hadapublished methodology,and9justifiedtheirrationale.

Appendices

Appendix1:Auks

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange: Razorbill

1-Extremestormsduringtherazorbillbreedingseasonhaveledtowide-spread nestdestruction,nestingfailureandanetreductioninannualpopulationproduction Newell,M.,etal."Effectsofanextremeweathereventonseabirdbreeding successataNorthSeacolony."MarineEcologyProgressSeries532 (2015):257-268. AsingleextremesummerstormontheIsleofMayresulted inwide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.Whileindividualstormscannotbeeasilybeattributedto climatechange,severestormsareincreasinglyfrequentinEurope.

2-Asseatemperatureshaveincreasedovertime,razorbillproductivityhas decreased,mostlikelyduetochangesinpreyavailability.

Lauria,V.,etal."Influenceofclimatechangeandtrophiccouplingacross fourtrophiclevelsintheCelticSea."(2012):e47408. Razorbillproductivity onSkomerIslanddeclinedoverthestudyperiod(1993–2007). Meanwhile,spring seasurfacetemperaturesignificantlyincreased.Razorbillproductivitywas correlatedwithspringseasurfacetemperatureinthepreviousyear.Thestudy suggeststhatseatemperatureaffectedtherazorbillsindirectly,throughthe availabilityofforagefish.

3-Keypreyspecieshaveshiftedtheirlife-cycle,likelyinresponsetoclimate change,butrazorbillshavenotadjustedinresponse.Thereisconcernthiscould resultintrophicmismatch,butnooveralleffectonbreedingsuccesshassofar beenobserved.

Burthe,S.,etal."Phenologicaltrendsandtrophicmismatchacrossmultiple levelsofaNorthSeapelagicfoodweb."MarineEcologyProgressSeries 454(2012):119-133. Timingofsandeelgrowthhaschangedsubstantially,but layingdatehasnotinrazorbills.Thislikelyhasresultedintrophicmismatch. However,todatenooveralleffectonbreedingsuccesshasbeenobserved. SeabirdobservationsbasedmostlyonIsleofMay. LittleAuk

1-Warmertemperaturescorrelatewithlongerforagingtripsandlowerlittleauk productivity,mostlikelyduetodecreasedpreyavailability.

Hovinen,J.E.H.,etal."Climatewarmingdecreasesthesurvivalofthe littleauk(Allealle),ahighArcticavianpredator."EcologyandEvolution 4.15(2014):3127-3138. AtseveralsitesinSvalbard,higherSSTisassociated withdecreasedadultsurvival,probablymediatedthroughpreyavailability. Suggestedmechanismisthatanincreaseintemperatureresultsinadecreasein seaiceandadecreaseinicealgalproductionwhichinturnresultsinlessfood qualityandavailability.ThetemperatureandinflowofwarmAtlanticwaterto theArcticincreasedduringthestudyperiod.

Hovinen,J.E.H.,etal."FledgingsuccessoflittleauksinthehighArctic: doprovisioningratesandthequalityofforaginggroundsmatter?."Polar Biology37.5(2014):665-674. HigherSSTincoloniesaroundSvalbard correlateswithlowerfledgingsuccess,thoughnotwithprovisioningrateby parents.Inatleastonecolony,thishasledtopopulationdecline.Mostlikely linkedtohigherSSTresultinginlowerpreyavailabilityquality. Ramírez,F.,etal."Seaicephenologyandprimaryproductivitypulses shapebreedingsuccessinArcticseabirds."ScientificReports7.1(2017): 1-9. Asabove,warmeryearswithlessseaiceresultinchangesintimingofkey preyspeciesavailability.Thisinturncorrelateswithlowerbreedingperformance inlittleauks.StudywasbasedaroundSpitsbergen,Svalbard.

Jakubas,D.,Wojczulanis-Jakubas,K.,andWalkusz,W."Responseof dovekietochangesinfoodavailability."Waterbirds30.3(2007):421-428. Thisstudylooksatsimilareffectstothoseabove,theynotewarmerwaters aroundSpitsbergenmeanslesseasilyaccessiblehigh-qualityfood,butthat adultsareabletocompensatesomewhatwithchangesintheirforagingstrategy. StudyalsonotesthattheNorthAtlantichaswarmedoverrecentyears.

2-Littleauksarebreedingearlierincorrelationwithwarmertemperatures,sofar nonegativeconsequencehasbeenobserved Moe,Børge,etal.“Climatechangeandphenologicalresponsesoftwo seabirdspeciesbreedinginthehigh-Arctic.”MarineEcologyProgressSeries 393(2009):235-246. LittleauksonSvalbardarebreedingearlierincorrelation withincreasesinairtemperatureinthespring.Thereasonforthisisnotclear, butmaybearesultofnestingsitesbeingavailableearlierduetosnowmelt. Thischangeinphenologymayormaynotmatchpreyavailability,whichmay leadtotrophicmismatchinthefuture.

3-Extremestormsduringthenon-breedingseasonhaveledtomassmortalityof littleauks(‘wrecks’)

Clairbaux,M.,etal."NorthAtlanticwintercyclonesstarveseabirds." CurrentBiology31.17(2021):3964-3971. Followingheavystormaction, seabirdmortalityincreasesduetoincreaseddifficultyforaging(ratherthan increasedenergeticcosts).Theauthorsuseamulti-speciesdataset(puffins, littleauks,commonmurres,andthick-billedmurres)overawideareaofthe Atlanticbasin.TheyconcludethatseabirdsaroundIcelandandtheBarentsSea (alongwithseveralN.Americansites)areparticularlyvulnerable.Climate changeislikelytobeacontributingfactortopresentandfuturestormmortality.

BlackGuillemot

1-Heavyrainfalleventsandhighwaterlevelhasledtofloodingofnestsandlower hatchingsuccessintheBaltic.Theauthorsnotethatsuchfloodingeventsarelikely tofurtherincrease.Debrisleftbystormsandfloodingcanalsomakelargeareasof shorelinelesssuitableforbreeding

Hof,A.R.,Crombag,J.A.H.M.,andAllen,A.M."TheecologyofBlack GuillemotCepphusgryllegryllechicksintheBalticSearegion:insightsinto theirdiet,survival,nestpredationandmomentoffledging."BirdStudy 65.3(2018):357-364. Stormsandincreasedwaterlevelleadstofloodingof nestsandlowerbreedingsuccessintheBaltic.Theauthorsnotethatsuch floodingeventsarelikelytofurtherincrease.Informationregardingdebriscomes frompersonalcorrespondencewithstakeholders.

2-RangeexpansionofAmericanmink,partlyassistedbyclimatechange,hasled toincreasedratesofpredationatguillemotcolonies

Buchadas,A.R.C.,andHof,A.R."Futurebreedingandforagingsitesofa southernedgepopulationofthelocallyendangeredBlackGuillemot Cepphusgrylle."BirdStudy64.3(2017):306-316. Blackguillemotsare particularlyvulnerabletopredationbyAmericanmink,whichiscurrently increasinginrangeandabundanceinEurope.Thisrangeexpansionhaslikely beenassistedbyclimatechangeandthereforepredationislikelytoworsen acrossthespeciesrange.ThestudyfocussesontheBalticbutsuggests anywheretheminkisexpandingislikelytohavesimilarissuesinthefuture.

3-Guillemothaveshiftedtheirlayingdate,mostlikelylinkedtoanincreaseinsea surfacetemperatureandpreyavailability

Greenwood,J.G."EarlierlayingbyBlackGuillemotsCepphusgryllein NorthernIrelandinresponsetoincreasingsea-surfacetemperature."Bird Study54.3(2007):378-379.

AtlanticPuffin

1-Changesinpuffins’preyavailabilityduringbreedingseasonhasledto

decreasedbreedingsuccess

Barrett,R.T."AtlanticpuffinFraterculaarcticaandcommonguillemotUria aalgechickdietandgrowthasindicatorsoffishstocksintheBarentsSea." MarineEcologyProgressSeries230(2002):275-287. Thevolumeofpuffin eggsintwoNorwegianpopulationsdeclinedoveraroughly30-yearperiod.Eggs weresmallerinyearswhencapelinandherringislessavailable,whichislinked toclimatechange.Thislikelyisalsoanindicatorofpopulationhealthandmay bedrivingdeclines.

Burthe,S.J.,etal."Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts."MarineEcologyProgressSeries507(2014):277295. PuffinproductivityandsurvivalhasdecreasedaroundtheForthandTay regionastemperaturehasincreased.Mostlikelylinkedtopreyavailability.Sea surfacetemperaturehasincreasedinthestudyregionbetween1980and2011.

Dunn,P.O.,andMøller,A.P.(eds)."EffectsofClimateChangeonBirds" 2ndedition,Oxford,OxfordAcademic(2019). Higherwatertemperaturein theNorwegianseahasresultedinashiftinherringstocktothenorth,anda spatialmismatchbetweenpuffinsandprey.

Durant,J.M.,etal."RegimeshiftsinthebreedingofanAtlanticpuffin population."EcologyLetters7.5(2004):388-394. IntheNorwegiansea, longtermfluctuationsinthewinterNAOindexhaveaffectedfoodavailability andthereforepuffinsuccessandbreedingtiming.Studyusedamulti-decadal datasetfromHernyken,NorthernNorway.

Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84. Severedeclinesofpuffinshaveoccurredinmostareasof Norway,causeisnotknownbutchangesinfoodabundanceandtimingare concludedtobethemostprobablecause.

Fayet,A.L.,etal."Localpreyshortagesdriveforagingcostsandbreeding successinadecliningseabird,theAtlanticpuffin."JournalofAnimal Ecology90.5(2021):1152-1164. Puffintrackingdatahasshownthatwhen theyareforcedtoforagefurther(usingdatafromIceland,NorwayandWales) breedingsuccessdecreases.Changesinfoodavailability–whichthestudy suggestshavecausedpuffinstoforagefurtherfromthecolonyandexpendmore energyatforaginggrounds–arecloselyrelatedtotemperature.

Frederiksen,M.,etal."Climate,copepodsandseabirdsintheboreal NortheastAtlantic–currentstateandfutureoutlook."GlobalChangeBiology 19.2(2013):364-372. DeclinesinpuffinbreedingsuccessontheIsleofMay

correlatewithmarineenvironmentalsuitabilityforcopepods(akeypreyfor manyfishandseabirds),whichhasdecreasedinrecentyears.Theauthors foundaweaker,non-significantlinkinNorway.

Hansen,E.S.,etal."Centennialrelationshipsbetweenoceantemperature andAtlanticpuffinproductionrevealshiftingdecennialtrends."Global ChangeBiology27(2021):3753-3764. Seasurfacetemperatureisastrong predictorofpuffinbreedingsuccessinabreedingpopulationinIceland,over bothdecennialandcentennialtimescales,mostlikelythroughsandeel abundanceduringthewinters.Milderwintersresultinfewersandeelsinthe followingsummer.Studyusesalongtermdataset(130years)basedon breedingsuccessinVestmannaeyjar,Iceland.

2-Changesinpuffins’preyavailabilityduringnon-breedingseasonhasledto increasedmortalityandpopulationdeclines

Anon“AtlanticpuffinFraterculaarctica”ScottishWildlifeTrustReport (2018)Availableat:https://scottishwildlifetrust.org.uk/wp-content/ uploads/2018/01/Puffin.docx. ColonydeclinesontheeastcoastofScotland areattributedtolackofpreyduringthebreedingandnon-breedingseason.The reportnotestheavailabilityofsuitablepreyduringthenon-breedingseasonis criticalforlong-termhealthofpuffinpopulations.

Harris,M.P.,etal."WinteringareasofadultAtlanticpuffinsFratercula arcticafromaNorthSeacolonyasrevealedbygeolocationtechnology." MarineBiology157.4(2010):827-836. Between1992and2008,IsleofMay puffinssufferedincreasingover-wintermortalityandshiftedtheirwintering distributionfromtheNorthSeatotheAtlantic.Thestudysuggeststhismightbe linkedtochangesintemperature,planktonpopulationsandfishpopulationsin theNorthSea.

3-Changesinvegetationhasledtofewersuitablepuffinnest-sites

Burthe,S.J.,etal."Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts."MarineEcologyProgressSeries507(2014):277295. Updateonthebelowitemconfirmingtheimpactsoftreemallowonpuffins andthescaleoftheprobleminScotland.

VanDerWal,R.,etal."Multipleanthropogenicchangescausebiodiversity lossthroughplantinvasion."GlobalChangeBiology14.6(2008):14281436. ExpansionoftreemallowLavateraarboreahas,inpartduetoclimate change,substantiallyreducedsuitablenestinghabitatforAtlanticpuffinsat severalcoloniesintheForthandTayregion.

4-Extremestormsduringthenon-breedingseasonhaveledtomass-mortalityof puffins(‘wrecks’)

Clairbaux,M.,etal."NorthAtlanticwintercyclonesstarveseabirds." CurrentBiology31.17(2021):3964-3971. Followingheavystormaction, seabirdmortalityincreasesduetoincreaseddifficultyforaging(ratherthan increasedenergeticcosts).Theauthorsuseamulti-speciesdataset(puffins, littleauks,commonmurres,andthick-billedmurres)overawideareaofthe Atlanticbasin.TheyconcludethatseabirdsaroundIcelandandtheBarentsSea (alongwithseveralN.Americansites)areparticularlyvulnerable.Climate changeislikelytobeacontributingfactortopresentandfuturestormmortality. Mitchell,I.,etal."Impactsofclimatechangeonseabirds,relevanttothe coastalandmarineenvironmentaroundtheUK."(2020):382-399. Winter stormscancausemassmortality(andhaverecentlyin2013/14storms),wrecks havebeenobservedoffthecoastofFranceandtheeastcoastofEngland.While individualstormscannoteasilybeattributedtoclimatechange,mostpredictions areconfidentextremeAtlanticstormswillbecomemorefrequent.

5-Puffinshavechangedtheirwinteringrange

Harris,M.P.,etal."WinteringareasofadultAtlanticpuffinsFratercula arcticafromaNorthSeacolonyasrevealedbygeolocationtechnology." MarineBiology157.4(2010):827-836. Between1992and2008,IsleofMay puffinssufferedincreasingover-wintermortalityandshiftedtheirwintering distributionfromtheNorthSeatotheAtlantic.Thestudysuggeststhismightbe linkedtochangesintemperature,planktonpopulationsandfishpopulationsin theNorthSea.

CommonMurre

1-High-windeventsinthenon-breedingseasonhaveledtomassmortalityof murresinrecentyears

Louzao,M.,etal."Thresholdresponsesinbirdmortalitydrivenbyextreme windevents."EcologicalIndicators99(2019):183-192. Highwindeventsin thewinterhavecausedseveralmassmortalityevents(“wrecks”)inNEAtlantic, thoughthisstudyfocussesonbodieswashedupinBayofBiscay.Study suggestshighwindeventsarelikelytobecomemorecommonandresultin moredeathsinthefuture.

2-Extremestormsduringthenon-breedingseasonhaveledtomassmortalityof murres(‘wrecks’)

Clairbaux,M.,etal."NorthAtlanticwintercyclonesstarveseabirds."

CurrentBiology31.17(2021):3964-3971. Followingheavystormaction,

seabirdmortalityincreasesduetoincreaseddifficultyforaging(ratherthan increasedenergeticcosts).Theauthorsuseamulti-speciesdataset(puffins, littleauks,commonmurres,andthick-billedmurres)overawideareaofthe Atlanticbasin.TheyconcludethatseabirdsaroundIcelandandtheBarentsSea (alongwithseveralN.Americansites)areparticularlyvulnerable.Climate changeislikelytobeacontributingfactortopresentandfuturestormmortality.

3-Morefrequentextremestormsduringmurres’breedingseasonhasincreased foragingdifficultyandreducedfoodfedtochicks

Finney,S.K.,Wanless,S.,andHarris,M.P."Theeffectofweather conditionsonthefeedingbehaviourofadivingbird,theCommonGuillemot Uriaaalge."JournalofAvianBiology(1999):23-30. Stormyweatheraffects thequantityandsizeoffoodthatadultscanprovidetochicks,andincreasesin summerstormfrequencymayresultinloweredforagingefficiency.Studywas conductedonIsleofMay.ExtremestormsintheAtlanticarelikelytobecome morefrequentinthefutureandfurtherdisruptthebreedingseason.

4-Extremestormsduringmurres’breedingseasonhaveledtowide-spreadnest destruction,nestingfailureandanetreductioninannualpopulationproduction Newell,M.,etal."Effectsofanextremeweathereventonseabirdbreeding successataNorthSeacolony."MarineEcologyProgressSeries532 (2015):257-268. AsingleextremesummerstormontheIsleofMayresulted inwide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.Whileindividualstormscannotbeeasilybeattributedto climatechange,itisgenerallybelievedthatseverestormsarebecomingmore common

5-Changesinmurres’preyavailabilityduringthebreedingseasonhasledto decreasedbreedingsuccess

Frederiksen,M.,etal."Climate,copepodsandseabirdsintheboreal NortheastAtlantic–currentstateandfutureoutlook."GlobalChangeBiology 19.2(2013):364-372. BreedingsuccessontheIsleofMaywasstrongly correlatedtosuitableclimateforlocalcopepods,andincreasesintemperature haveloweredsuitabilityforcopepodsandthereforebreedingsuccessinrecent years.Projectionsalsoshowthatthisdropinsuitabilitywillcontinueandworsen inthefuture.Interestingly,theauthorsdidnotfindevidenceofsuchalinkin Rost,Norway. Irons,D.B.,etal."Fluctuationsincircumpolarseabirdpopulationslinkedto climateoscillations."GlobalChangeBiology14.7(2008):1455-1463. The authorsfind,usingamulti-decadedataset,thatmurrepopulationsizeacross

theArcticisstronglycorrelatedtoseasurfacetemperature.Rapidtemperature shifts(eitherhotterorcooler)resultedinadecreaseinpopulationsize.Note: thisstudydoesnotexplicitlyinvestigateanthropogenicclimatechange,butdoes showaclearlinkagebetweenrapidclimatechangeandpopulationdeclines.

6-Murresaremorelikelytoskipbreedinginwarmerweather,andthisbehaviour isbecomingmorefrequent.Whilethisisacauseforconcern,itisunclearwhat effectthiswillhaveonthepopulationinthelong-term Reed,T.E.,Harris,M.P.,andWanless,S."Skippedbreedingincommon guillemotsinachangingclimate:restraintorconstraint?"Frontiersin EcologyandEvolution3(2015):1. Murres(akaguillemots)skipbreeding morefrequentlyin/followingwarmyears,andseatemperatureshaveincreased inthestudyarea(NorthSea)overrecentdecades.thismayincreaseinthe future.However,thelongtermconsequencesofthisimpactonthepopulation areunclear.StudyconductedonIsleofMay,Scotland.

7-Heatwaveshaveresultedinsignificantmurrechickmortality.Thefrequencyand severityofheatwavesislikelytoincrease Ballstaedt,Elmar(personalcorrespondance);Seealsohttps://www. jordsand.eu/2018/08/14/bruterfolg-deutscher-seev%C3%B6gel-durchwetterkapriolen-schlecht-wie-lange-nicht-mehr Theheatwaveofsummer 2018resultedinfewerbreedingattemptsandincreasedchickmortalityinmany speciesonHelgoland,mostlikelyduetoheatstress.Manyseabirdson Helgolandaredecliningwhichcouldinpartbeduetoclimatechange.

8-Commonmurreshavechangedtheirphenology,potentiallyinresponseto climatechangebutthemechanismisunclear

Wanless,S.,etal."Laterbreedinginnortherngannetsintheeastern Atlantic."MarineEcologyProgressSeries370(2008):263-269. Overa periodofroughly30years,thelayingdateofcommonmurresintheNorthSea (IsleofMayandFarneIslands)becamesignificantlylater.Thestudydidnot identifyamechanismfordelayedbreedinginawarmingNorthSea,butdidfind acorrelationbetweencombinedauk/kittiwakelayingdatesandthewinterNAO index.

9-Ashifttowardswarmer,drierandcalmerconditionshascorrelatedwithhigher populationabundance.Mechanismunknown,butlikelymediatedthroughprey availabilityandlowerenergeticcosts.

Hemery,G.,etal."Detectingtheimpactofoceano-climaticchangeson marineecosystemsusingamultivariateindex:thecaseoftheBayof Biscay(NorthAtlantic-EuropeanOcean)."GlobalChangeBiology14.1

(2008):27-38. AbundanceofcommonmurresintheBayofBiscayincreased from1974to2000.Annualabundance(at-seacounts)waspositivelycorrelated withalocalmultivariateclimateindex(combining11oceanicandatmospheric variables)andthelarge-scalewinterNAOindex.Murresappeartobenefitfroma trendtowardswarmer,drieryearswithcalmerseasurfaceconditions.

Thick-billedMurre

1-Changesinthick-billedmurres’preyavailabilityduringthenon-breedingseason hasledtoincreasedmortality

Descamps,S.,Strøm,H.,andSteen,H.."Declineofanarctictoppredator: synchronyincolonysizefluctuations,riskofextinctionandthesubpolar gyre."Oecologia173.4(2013):1271-1282. ManycoloniesinSvalbardare declining,andiftrendscontinuethereisariskoflocalextinction.Declines stronglycorrelatewithmarinechange,thoughtheexactmechanismisunknown.

Authorssuggestthatdeteriorationofthefeedingconditionsinthewinter affectedbirdsurvival,particularlyjuvenilesurvival,andthatlocalvariationsin springandsummerconditionsaffectedbreedingpropensityandbreeding successofmurres.

Sandvik,H.,etal."Theeffectofclimateonadultsurvivalinfivespeciesof NorthAtlanticseabirds."JournalofAnimalEcology74.5(2005):817-831.

Authorsfoundthatboththecommonmurres(guillemots)andthick-billedmurres (Brünnich’sguillemots)werenegativelyaffectedbywarmertemperatures causingalterationstotheirfoodwebs,theynotethatthesetrendsarelikelyto continue.Thedataspanned14yearsofobservationatacolonyonHornøya,off NorthernNorwayinthewesternBarentsSea

2-Changesinthick-billedmurres’preyavailabilityduringthebreedingseasonhas ledtodecreasedbreedingsuccess

Descamps,S.,Strøm,H.,andSteen,H.."Declineofanarctictoppredator: synchronyincolonysizefluctuations,riskofextinctionandthesubpolar gyre."Oecologia173.4(2013):1271-1282. LocalvariationsinSvalbard springandsummerconditionsaffectedbreedingpropensityandbreeding successofmurres.See1)formoredetails.

Garðarsson,A.,Guðmundsson,G.A.,andLilliendahl,K."Svartfuglí íslenskumfuglabjörgum2006–2008."Bliki33(2019):35-46. Reviewsthe populationtrendsinvariousseabirdspeciesinIceland.Particularlyhighlightsthe drasticdeclineofthick-billedmurres(Brünnich’sguillemots)acrossIceland. Sharpdeclinescorrespondtocrashinkeypreyspeciesandchangesinmarine ecosystemslinkedtorapidtemperaturechange.

3-Changesinthick-billedmurres’preyavailabilityduringthebreedingseasonhas ledtoincreasedmortality

Fluhr,J.,etal."WeakeningofthesubpolargyreasakeydriverofNorth Atlanticseabirddemography:acasestudywithBrünnich’sguillemotsin Svalbard."MarineEcologyProgressSeries563(2017):1-11. Anupdateand expansiononthepreviouspaper,focussingonmurresonBearIsland,Svalbard. ConfirmsstrongcorrelationofadultannualsurvivalandthestrengthofAtlantic subpolargyre.

4-Thick-billedmurrepopulationsaretypicallysmalleranddeclineinareaswith increasingseatemperatures.Mechanismunclear.

Bonnet-Lebrun,A.S.,etal."Coldcomfort:Arcticseabirdsfindrefugiafrom climatechangeandpotentialcompetitioninmarginalicezonesand�ords." Ambio51.2(2022):345-354.Thick-billedmurres(Brünnich’sguillemots) populationsinIcelandhavedeclinedincorrelationwithrisingseasurface temperatures.Inaddition,populationsassociatedwithhigherseatemperatures havedeclinedfasterandtendtobesmallerthanthosenearrefugiaofcold water.Theauthorsinvestigatetheroleofcompetition(withlittlesignificant effect),butlinktovariousIcelandicstudieswhichprovideevidenceforprey availabilitybeingthemainreasonbehindthedeclines

Irons,D.B.,etal."Fluctuationsincircumpolarseabirdpopulationslinkedto climateoscillations."GlobalChangeBiology14.7(2008):1455-1463. The authorsfind,usingamulti-decadedataset,thatmurrepopulationsizeacrossits rangeintheArcticisstronglycorrelatedtoseasurfacetemperature.Rapid temperatureshifts(eitherhotterorcooler)resultedinadecreaseinpopulation size,probablymediatedthroughchangesinunderlyingfood-webs.Note:this studydoesnotexplicitlyinvestigateanthropogenicclimatechange,butdoes showaclearlinkagebetweenrapidclimatechangeandpopulationdeclines.

5-Extremestormsduringthenon-breedingseasonhaveledtomassmortalityof murres(‘wrecks’)

Clairbaux,M.,etal."NorthAtlanticwintercyclonesstarveseabirds." CurrentBiology31.17(2021):3964-3971. Followingheavystormaction, seabirdmortalityincreasesduetoincreaseddifficultyforaging(ratherthan increasedenergeticcosts).Theauthorsuseamulti-speciesdataset(puffins, littleauks,commonmurres,andthick-billedmurres)overawideareaofthe Atlanticbasin.TheyconcludethatseabirdsaroundIcelandandtheBarentsSea (alongwithseveralN.Americansites)areparticularlyvulnerable.Climate changeislikelytobeacontributingfactortopresentandfuturestormmortality.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

Forrazorbill,littleauk,blackguillemot,Atlanticpuffin,commonmurre,andthickbilledmurreweincludedthefollowingterrestrialvariables:meantemperatureof thewarmestmonth,precipitationduringbreedingseason,isolationoflandmass, areaoflandmass,distancetosea.

Forrazorbill,littleauk,blackguillemot,Atlanticpuffin,commonmurre,andthickbilledmurreweincludedthefollowingmarinevariables:seasurfacetemperature (duringthewinter),salinity,maximumchlorophyllconcentration,bathymetry (depthandvariance).

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2.

Underlyingdataweredownloadedfrom: Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies. Razorbill keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytes tobianus),herring(Clupeaharengus),capelin(Mallotusvillosus)andsprat(Sprattus sprattus).Preyspecieslistwascompiledfrom:

Barrett,R.T."Thediet,growthandsurvivalofRazorbillAlcatordachicksin thesouthernBarentsSea."OrnisNorvegica38(2015):25-31.

Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84.

LittleAuk keypreyspecies: Calanusglacialis, Calanushyperboreus and Apherusa glacialis.Notethatsincedataregardingclimatechangeandcopepodrangeshifts arenotreadilyavailable,afullpreylossassessmentcouldnotbecarriedoutfor thisspecies.Preyspecieslistwascompiledfrom:

Amélineau,F.,etal."Arcticclimatechangeandpollutionimpactlittleauk foragingandfitnessacrossadecade."Scientificreports9.1(2019):1-15.

Harding,A.M.A.,etal."Estimatingpreycaptureratesofaplanktivorous seabird,thelittleauk(Allealle),usingdiet,divingbehaviour,andenergy consumption."PolarBiology32.5(2009):785-796.

BlackGuillemot keypreyspecies:sandeelspecies(Ammodytesmarinus), butterfish(Pholisgunnellus),eelpout(Zoarcesviviparus)andseascorpion(Taurulus bubalis).Preyspecieslistwascompiledfrom:

Barrett,R.T.,andAnker-Nilssen,T."Egg-laying,chickgrowthandfoodof BlackGuillemotsCepphusgrylleinNorthNorway."FaunaNorvegica,Series C20.2(1997):69-79.

BirdLifeInternational.“Speciesfactsheet:Cepphusgrylle.”(2021) Downloadedfromhttp://www.birdlife.orgon01/06/2021.

Ewins,P.J."ThedietofblackguillemotsCepphusgrylleinShetland." Ecography13.2(1990):90-97.

Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84.

Hario,M."ChickgrowthandnestdepartureinBalticBlackGuillemots Cepphusgrylle."OrnisFennica78.3(2001):97-108.

Hof,A.R.,Crombag,J.A.H.M.,andAllen,A.M."TheecologyofBlack GuillemotCepphusgryllegryllechicksintheBalticSearegion:insightsinto theirdiet,survival,nestpredationandmomentoffledging."BirdStudy 65.3(2018):357-364.

AtlanticPuffin keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),herring(Clupeaharengus),capelin(Mallotusvillosus)and sprat(Sprattussprattus).Preyspecieslistwascompiledfrom:

BirdLifeInternational.“Speciesfactsheet:Fraterculaarctica.”(2021) Downloadedfromhttp://www.birdlife.orgon01/06/2021.

Fayet,A.L.,etal."Localpreyshortagesdriveforagingcostsandbreeding successinadecliningseabird,theAtlanticpuffin."JournalofAnimal Ecology90.5(2021):1152-1164.

CommonMurre keypreyspecies:sprat(Sprattussprattus),sandeelsspecies (Ammodytesmarinus and Ammodytestobianus),capelin(Mallotusvillosus),herring

(Clupeaharengus),Atlanticcod(Gadusmorhua),saithe(Pollachiusvirens)and haddock(Melanogrammusaeglefinus).Preyspecieslistwascompiledfrom: Ainley,D.G.,Nettleship,D.N.,andStorey,A.E.“CommonMurre(Uria aalge),version2.0.”InBirdsoftheWorld(S.M.Billerman,P.G.Rodewald, andB.K.Keeney,Editors).CornellLabofOrnithology,Ithaca,NY,USA (2021).

BirdLifeInternational.“Speciesfactsheet:Uriaaalge.”(2021)Downloaded fromhttp://www.birdlife.orgon01/06/2021.

Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84.

Thick-billedMurre keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),herring(Clupeaharengus),capelin(Mallotusvillosus), Atlanticcod(Gadusmorhua)andpolarcod(Boreogadussaida).Preyspecieslist wascompiledfrom: Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84.

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

Amélineau,F.,etal.“Arcticclimatechangeandpollutionimpactlittleauk foragingandfitnessacrossadecade.”Scientificreports9.1(2019):1-15.

AtlanticPuffin

SomecoloniesinNorthAmericahavechangedtheirlayingphenology,presumably

inresponsetotemperatureand/orpreyavailability.Somerecentobservationshave reportedthishasalsooccurredinEurope.

Major,H.L.,etal.“Contrastingphenologicalanddemographicresponsesof AtlanticPuffin(Fraterculaarctica)andRazorbill(Alcatorda)toclimate changeintheGulfofMaine.”ElemSciAnth9.1(2021):00033.

ErpurHansen(PersonalCorrespondence)

Thick-billedMurre

Thick-billedmurresareknowntobeimpactedbyclimatechangeoutsideofEurope. Impactsincludeincreasedpredationbypolarbears,increasedparasitismby mosquitoes(leadingtobreedingfailure),andincreasedmortalitycausedbyalgal blooms.ChangesinthemarineecosysteminthecanadianhighArctic,drivenby climatechange,hasresultedinhigherconcentrationsofmercurybioaccumulatedin thick-billedmurres.Nolong-termimpactonpopulationhealthhasbeenobserved sofar

Braune,B.M.,etal.“Changesinfoodwebstructurealtertrendsof mercuryuptakeattwoseabirdcoloniesintheCanadianArctic.” Environmentalscience&technology48.22(2014):13246-13252.

Gaston,A.J.,andElliott,K.H.“Effectsofclimate-inducedchangesin parasitism,predationandpredator-predatorinteractionsonreproduction andsurvivalofanArcticmarinebird.”Arctic(2013):43-51.

Kuletz,K.etal.“Chapter3.5:Seabirds”in“StateoftheArcticMarine BiodiversityReport”.ConservationofArcticFloraandFaunaInternational Secretariat(2017):129-147.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,aukspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetheraukshaveeither1)Specialisedhabitat and/ormicrohabitatrequirement2)Environmentaltolerancesorthresholds(atany lifestage)thatarelikelytobeexceededduetoclimatechange3)Dependenceon environmentaltriggersthatarelikelytobedisruptedbyclimatechange,4)

Dependenceoninterspecificinteractionsthatarelikelytobedisruptedbyclimate changeor5)Highrarity.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof

theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,aukspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetheraukshaveeither:1)Highphenotypic plasticity.2)Highdispersalabilityor3)Highevolvability. Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:DucksandPhalaropes

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange:

Long-tailedDuck

1-WinteringpopulationsinEuropehavedeclinedduetoclimatechange-driven changesinpredationinbreedingareasoutsideofEurope.

Hario,M.,Rintala,J.,andNordenswan,G."DynamicsofwinteringlongtailedducksintheBalticSea–theconnectionwithlemmingcycles,oil disasters,andhunting."SuomenRiista55(2009):83-96. Wintering populationsintheBaltichaverapidlydeclined,inpartbecauseoftheeffectsof climatechangeonkeybreedingsitesoutsideofEurope.Duetochangesin lemmingavailability,predatorssuchasArcticfoxeshaveswappedtopreyingon duckeggsandyoungasalternativepreywhich,inturn,hasresultedin decreasedbreedingsuccessoflong-tailedduckClangulahyemalisontheTaimyr Peninsula.

Hearn,R.D.,Harrison,A.L.,andCranswick,P.A."Internationalsingle speciesactionplanfortheconservationofthelong-tailedduckClangula hyemalis,2016–2025."AEWATechnicalSeriesSpeciesActionPlan:57 (2015). Expandsandupdatestheworkabove,theauthorsbelievechangesin predationhaveaffectedpopulationsacrosswesternSiberiaandnorthernEurope

2-Rangeexpansionofredfoxesfollowingmilderwintershasledtopredationof ducksmuchfurthernorththanpreviously,andmaybethreateningtheviabilityof northernpopulations.

Hearn,R.D.,Harrison,A.L.,andCranswick,P.A."Internationalsingle speciesactionplanfortheconservationofthelong-tailedduckClangula hyemalis,2016–2025."AEWATechnicalSeriesSpeciesActionPlan:57 (2015). Rangeexpansionofpredatorssuchasredfox(Vulpesvulpes)maybe influencingpredator-preyrelationshipsintheArcticbreedinggrounds,and appearstobethreateningtheviabilityofthesmallFinnishLaplandbreeding populationoflong-tailedducks.Additionalinformationontheriskandspreadof redfoxesduetoclimatechangewasprovidedbystakeholders.

3-Competitionwithnon-nativegobieshascausedlong-tailedduckstoswitchprey, thoughtherehasbeennoobservedchangeinmortalityorcondition.Gobyinvasion

mayhavebeenassistedbyclimatechange,thoughcurrentlythisisspeculative. Behrens,J.W.,etal.“Seasonaldepthdistributionandthermalexperience ofthenon-indigenousroundgobyNeogobiusmelanostomusintheBaltic Sea:implicationstokeytrophicrelations.”BiologicalInvasions24.2 (2022):527-541. Thisstudydoesnotmakealinkdirectlytoseabirds,butis providedassupplementaryinformationmakingthelinkbetweengobiesand climatechangeclearer.Gobiesstronglypreferwarmwater,whichexplainwhy theyhavenowcolonisedtheBalticasclimatechangehasresultedinwarmer winters.Italsosuggestsfurtherclimatechangewillassistfurtherspread.

Skabeikis,A.,etal.“Effectofroundgoby(Neogobiusmelanostomus) invasiononbluemussel(Mytilusedulistrossulus)populationandwinter dietofthelong-tailedduck(Clangulahyemalis).”BiologicalInvasions21.3 (2019):911-923. ThebenthicroundgobyhasrecentlycolonisedtheBaltic, whichmayhavebeenfacilitatedbyclimatechange(RamunasŽydelis,personal communication),asgobiesstronglypreferwarmerwater(seeBehrenset al.2022below).Competitionwithgobieshascausedlong-tailedduckstoswitch prey,andtherehasbeennoobservedchangeinmortalityorcondition. However,furtherclimatechangecouldpromotegobyexpansionandfurther competition.

HarlequinDuck

1-Populationhasredistributed,withsomepopulationsgrowingandothers shrinking,mostlikelyduetoshiftsinpreyspeciescausedbyclimatechange Gardarsson,A.“HarlequinDucksinIceland.”Waterbirds31.sp2(2008):814.

Gardarsson,A.,andEinarsson,Á."Relationshipsamongfood,reproductive successanddensityofharlequinducksontheRiverLaxáatMyvatn, Iceland(1975-2002)."Waterbirds31.sp2(2008):84-91. Usinga multidecadedatasettheauthorsconcludethatsouthernpopulationsinIceland havedecreased1961-2001whilenorthernpopulationshaveincreased.Thisis likelyduetochangesinblackflyabundance,whichinturnisatleastpartlydue towarmerspringsandsummers

VelvetScoter

1-Scotersarestartingtheirautumnmigrationsignificantlylaterinresponseto changingclimate.

Lehikoinen,A.,andJaatinen,K."Delayedautumnmigrationinnorthern Europeanwaterfowl."JournalofOrnithology153.2(2012):563-570. Scoter phenologychangedbetween1979and2009,consistentwithexpectationsunder awarminglocalclimate.Autumnmigrationisoccurringlater,birdsarearriving

later.StudycarriedoutusinglongtermdatafromHankoObservatory,southern Finland

2-Winteringpopulationshaveredistributed,mostlikelyduetolackofpreycaused atleastpartlybyclimatechange.

Tolon,V.,etal.“EtatdespopulationsdemacreusesenEurope,enFrance etenBasse-Normandieetanalysedesprincipauxfacteursdedistribution“. ReportforMaisondel’Estuaire(2013). Winteringpopulationsofscotersoff thecoastofFrancearedecliningandinsomecaseshavedisappeared.Causeis uncertain,butprobablytheyhaveredistributedratherthandied,andhave shiftedinresponsetoreducedpreyavailability.Thereareseveralunderlying causes,butclimatechangeislikelytobeacontributingfactor.

CommonScoter

1-Winteringpopulationshaveredistributed,mostlikelyduetolackofpreycaused atleastpartlybyclimatechange.

Tolon,V.,etal.“EtatdespopulationsdemacreusesenEurope,enFrance etenBasse-Normandieetanalysedesprincipauxfacteursdedistribution“. ReportforMaisondel’Estuaire(2013). Winteringpopulationsofscotersoff thecoastofFrancearedecliningandinsomecaseshavedisappeared.Causeis uncertain,butprobablytheyhaveredistributedratherthandied,andhave shiftedinresponsetoreducedpreyavailability.Thereareseveralunderlying causes,butclimatechangeislikelytobeacontributingfactor.

Red-neckedPhalarope

1-Red-neckedphalaropeshaveshiftednorthinFinland,themostsoutherly populationsaredecliningwhilenortherlypopulationsareincreasing.Thisshiftisin correlationwithclimatechange,buttheunderlyingmechanismisnotcertain Virkkala,R.,etal.“Matchingtrendsbetweenrecentdistributionalchanges ofnorthern-borealbirdsandspecies-climatemodelpredictions.”Biological Conservation172(2014):124-127. Red-neckedphalaropeshaveshiftednorth inFinland,thecentraldensityofthepopulationhasshiftedsignificantly northwards.Thisshiftisincorrelationwithclimatechange,buttheunderlying mechanismisnotcertain.

Steller’sEider

1-ManySteller’seidersintheBaltichavechangedwinteringareatotheWhite Sea,mostlikelyduetodecreasesinseaice.Thismayalsobeassociatedwithan overallpopulationdecline,butthisisuncertain Aarvak,T.,etal.“TheEuropeanwinteringpopulationofSteller’sEider Polystictastellerireassessed.”BirdConservationInternational23.3(2013):

337-343. ThenumberofSteller’seiderswinteringintheBaltichasdropped sharply.Thisislikelyduetobothadecreaseinpopulationsizeanda redistributionofwinteringareatotheWhitesea,mostlikelyduetodecreasesin seaiceandagreaterareaofopenwater. Žydelis,R.,etal.“RecentchangesinthestatusofSteller’sEiderPolysticta stelleriwinteringinEurope:adeclineorredistribution?.”BirdConservation International16.3(2006):217-236. Thispaperprecedestheoneaboveand concludesthatalthoughtherewasaredistributiontowardstheKolaPeninsula, thepopulationmaybedecliningasawhole.

CommonEider

1-Milderwinterandsummerweatherhaveresultedinbetteraverageadult condition,andthereforebetterbreedingsuccess.Insomeareasthishasresultedin localpopulationsincreases.

D’Alba,L.,Monaghan,P.,andNager,R.G."Advancesinlayingdateand increasingpopulationsizesuggestpositiveresponsestoclimatechangein commoneidersSomateriamollissimainIceland."Ibis152.1(2010):1928. Usinga30yeardatasetinIceland,theauthorsbelieveclimatechangeisa majordriverbehindthepopulationincrease.Mildersummersmeanmorenests, becausefewerfemalesskipbreeding(astheyareinhighercondition)

2-Eidershaveshiftedtheirphenologyinresponsetomilderwintersandlay earlier.

D’Alba,L.,Monaghan,P.,andNager,R.G."Advancesinlayingdateand increasingpopulationsizesuggestpositiveresponsestoclimatechangein commoneidersSomateriamollissimainIceland."Ibis152.1(2010):1928. InIceland,eiderslaidearlierfollowingwarmerwinters.Theexactreasonis uncertainbutcouldbebecauseadultsareinbetterconditionfollowingwinter,or becausekeypreyspecies(especiallymussels)areavailableearlierinmilder winters.

3-Duetoalackofseaicedrivenbyclimatechange,polarbearsarebecoming morenumerousaroundbirdcoloniesduringthesummerandaremoreheavily predatingoneiderpopulations

Prop,J.,etal.“Climatechangeandtheincreasingimpactofpolarbearson birdpopulations.”FrontiersinEcologyandEvolution3(2015):33. Study conductedonSvalbard,polarbearsappeartobeswappingpreyspeciesfrom sealsduetoalackofseaice.Severalbirdspeciesareincreasinglypredated, prominentlyeiders.

4-EarliermeltofseaiceinspringhasresultedinadecreaseinpredationbyArctic

foxes,astheycannotaccessbreedingcolonieswithoutthepresenceofseaice Hanssen,S.A.,etal."Anaturalantipredationexperiment:predatorcontrol andreducedseaiceincreasescolonysizeinalong-livedduck."Ecology andEvolution3.10(2013):3554-3564. Acrosstwoeidercoloniesin Spitsbergen,populationdensityisgreaterinyearswithlessseaiceinApril.The studysuggeststhisprovidesearlier/longeraccesstofoodandreducespredation byArcticfoxes.Thestudyuseda30-yeardataset,andnotesthatAprilseaice coverhasdeclinedoverthisperiod.

5-Earliermeltofseaiceinspringhasresultedinanincreaseineiderpopulation density,aseidershaveearlierandlongeraccesstohigh-qualityprey. Hanssen,S.A.,etal."Anaturalantipredationexperiment:predatorcontrol andreducedseaiceincreasescolonysizeinalong-livedduck."Ecology andEvolution3.10(2013):3554-3564. Acrosstwoeidercoloniesin Spitsbergen,populationdensityisgreaterinyearswithlessseaiceinApril.The studysuggeststhisprovidesearlier/longeraccesstofoodandreducespredation byArcticfoxes.Thestudyuseda30-yeardataset,andnotesthatAprilseaice coverhasdeclinedoverthisperiod.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

Forlong-tailedduck,harlequinduck,velvetscoter,commonscoter,red-breasted merganser,redphalarope,andred-neckedphalaropeweincludedthefollowing terrestrialvariables:Meantemperatureofthewarmestmonth,precipitationduring breedingseason,distancetosea

ForSteller’seider,commoneider,andkingeiderweincludedthefollowing terrestrialvariables:meantemperatureofthewarmestmonth,precipitationduring

breedingseason,isolationoflandmass,areaoflandmass,distancetosea.

ForSteller’seider,commoneider,andkingeiderweincludedthefollowingmarine variables:seasurfacetemperature(duringthewinter),salinity,maximum chlorophyllconcentration,bathymetry(depthandvariance).

Severalothervariablesmaystronglyinfluencethedistributionofducksand phalaropesanditisnotpossibletoincludeallpossiblevariablesinagivenmodel. Howeverthefollowingvariableshavepreviouslybeenfoundtobeimportantto predictingthedistributionofducksandphalaropesinEurope:freshwaterdepth, freshwaterph,freshwaterchlorophyllconcentration,seabedsubstrate(sediment granulometry).Forlocalassessmentsofclimatechange,werecommendthese variablesarestronglyconsidered.Wehopetoincorporatethesevariablesinto futureversionsofthisguidancedocument.

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2. Underlyingdataweredownloadedfrom: Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata 1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

Long-tailedDuck keypreyspecies:Thisspeciesreliesonpredominantlyaquatic invertebratesonbreedinggrounds,andavarietyofinvertebrates,notablyMytilus species,andfishinwinter.Nokeyspeciescouldbeidentifiedsocurrentlythereis nokeypreyassessmentforthisspecies

HarlequinDuck keypreyspecies:Insummer,thisspeciespreysmainlyonvarious midges,blackflyandcaddisflies.Inwinter,nokeyspeciescouldbeidentifiedas dietisextremelyvaried.Currentlythisspeciesdoesnothaveakeyprey assessment

VelvetScoterkeypreyspecies: Myaarenaria,Cerastodermaglaucum,Saduria entomon,Euspiranitida,Macomabaltica,CerastodermalamarckiandSpisula subtruncata. Preyspecieslistwascompiledfrom:

Morkune,R.,etal.“Triplestableisotopeanalysistoestimatethedietofthe VelvetScoter(Melanittafusca)intheBalticSea.”PeerJ6(2018):e5128.

Durinck,J,etal.“DietofthecommonscoterMelanittanigraandvelvet scoterMelanittafuscawinteringintheNorthSea.”OrnisFennica70.4 (1993):215-218.

Stempniewicz,L."ThefoodintakeoftwoScotersMelanittafuscaandM. nigrawinteringintheGulfofGdańsk,PolishBalticcoast."VårFågelv., Suppl11(1986):211-214..

CommonScoter keypreyspecies: Spisulasubtruncata,Myatruncata,Macoma

balthica,MytilisedulisandDonaxvittatus.Thisspeciesalsopreysoninsects, especiallychironomidlarvaeandcladocerans.Presentlythesearenotincludedin thekeypreyassessment,duetodatalimitations..Preyspecieslistwascompiled from:

Carboneras,C.andKirwan,G.M.“CommonScoter(Melanittanigra), version1.0.”InBirdsoftheWorld(J.delHoyo,A.Elliott,J.Sargatal,D.A. Christie,andE.deJuana,Editors).CornellLabofOrnithology,Ithaca,NY, USA(2020).

Durinck,J.,etal.“DietofthecommonscoterMelanittanigraandvelvet scoterMelanittafuscawinteringintheNorthSea.”OrnisFennica70.4 (1993):215-218.

Hartley,C.“StatusanddistributionofCommonScotersontheSolway Firth.”BritishBirds100.5(2007):280.

Stempniewicz,L.“ThefoodintakeoftwoScotersMelanittafuscaandM. nigrawinteringintheGulfofGdansk,PolishBalticcoast.”VårFågelv., Suppl11(1986):211-214.

Red-breastedMerganser keypreyspecies:stickleback(Gasterosteusaculeatus). Thisspeciesconsumesawidevarietyoffishspecies,bothmarineandfreshwater.

Freshwaterspecies,especially Salmosalar, arelikelyveryimportantbutfreshwater speciesarecurrentlynotincludedinthekeypreyassessment.Whileitpreyson othermarinespecies,nootherkeyspeciescouldbeidentified.Preyspecieslistwas compiledfrom:

Bengtson,S.-A."FoodandfeedingofdivingducksbreedingatLake Myvatn,Iceland."OrnisFennicaVol.48(1971):77-92.

Craik,S.,Pearce,J.,andTitman,R.D.“Red-breastedMerganser(Mergus serrator),version1.0.”InBirdsoftheWorld(S.M.Billerman,Editor). CornellLabofOrnithology,Ithaca,NY,USA(2020).

Feltham,M.“Thedietofred-breastedmergansers(Mergusserrator)during thesmoltruninNEScotland:theimportanceofsalmon(Salmosalar) smoltsandparr.”JournalofZoology222.2(1990):285-292.

RedPhalarope keypreyspecies:Thisspecieshasabroaddietofinvertebrates, thatvariesacrosspopulations.Keyspeciesgroupsincludemarinecopepodsand amphipods,aswellasadultandlarvalmidges,gnatsandcraneflies.Currently thereisnokeypreyassessment,duetolackofdata.

Red-neckedPhalarope keypreyspecies:Duringthebreedingspeciesthisspecies

feedprimarilyonmidges(adultsandlarvae),alongwithmanyotherinsectspecies. Atsea,itfeedsmostlyoncopepodsandkrillspecies.Currentlythereisnokeyprey assessmentforthisspecies

Steller’sEiderkeypreyspecies: Margariteshelicinus,Skeneopsisplanorbis, Mytilusedulis,Turtoniaminuta,Gammarusoceanicus,Ampithoerubricata,Idotea emarginataandIdoteagranulosa.Thisspeciesalsopreysonvariousmidgeand craneflylarvae,especiallyduringthebreedingseason.Theseterrestrialspeciesare notincludedinthekeypreyassessment.Preyspecieslistwascompiledfrom

Bustnes,JanO.,etal.“ThedietofSteller’sEiderswinteringin Varanger�ord,northernNorway.”TheWilsonJournalofOrnithology112.1 (2000):8-13.

Fredrickson,L.H.“Steller'sEider(Polystictastelleri),version1.0.”InBirds oftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca, NY,USA(2020).

Nygård,T.,Frantzen,B.,andŠvažas,Saulius."Steller'sEidersPolysticta stelleriwinteringinEurope:numbers,distributionandorigin."Wildfowl 46.46(1995):140-156.

CommonEider keypreyspecies: Mytilusedulis,Modiolusmodiolus,Tonicella marmorea,Buccinumundatum,HyasaraneusandLacunavincta.Preyspecieslist wascompiledfrom:

Bustnes,J.O.,andErikstad,K.E."Thedietsofsympatricwintering populationsofCommonEiderSomateriamollissimaandKingEiderS. spectabilisinNorthernNorway."OrnisFennica65.4(1988):163-168.

Goudie,R.I.,Robertson,G.J.,andReed,A.“CommonEider(Somateria mollissima),version1.0”.InBirdsoftheWorld(S.M.Billerman,Editor). CornellLabofOrnithology,Ithaca,NY,USA(2020).

Kristjánsson,T.Ö.,Jónsson,J.E.,andSvavarsson,J.“Springdietof commoneiders(Somateriamollissima)inBreiða�örður,WestIceland, indicatesnon-bivalvepreferences.”PolarBiology36.1(2013):51-59.

KingEider keypreyspecies: Ophiopholisaculeata,Strongylocentrotus droebachiensis,Asteriasrubens,Boreotrophonclathratus,Musculusdiscors, Modiolariamodiolus,Chlamysislandica,Myatruncata,Mytilusedulis, CiliatocardiumciliatumandHiatellaarctica. Preyspecieslistwascompiledfrom:

Powell,A.N.andSuydam,R.S.“KingEider(Somateriaspectabilis), version1.0.”InBirdsoftheWorld(S.M.Billerman,Editor).CornellLabof

Ornithology,Ithaca,NY,USA(2020).

Frimer,O.“DietofmoultingkingeidersSomateriaspectabilisatDisko Island,WestGreenland.”OrnisFennica74(1997):187-194.

Merkel,F.R.,etal.“ThedietofkingeiderswinteringinNuuk,Southwest Greenland,withreferencetosympatricwinteringcommoneiders.”Polar Biology30.12(2007):1593-1597.

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

VelvetScoter

ClimatechangehascontributedtodeclinesofscoterpopulationsinNorthAmerica.

Earlierspringsnowmelthaslikelyledtoatrophicmismatchandlowerbreeding successinscoters.

Drever,M.C.,etal.“Populationvulnerabilitytoclimatechangelinkedto timingofbreedinginborealducks.”GlobalChangeBiology18.2(2012): 480-492.

CommonScoter

ClimatechangehascontributedtodeclinesofscoterpopulationsinNorthAmerica. Earlierspringsnowmelthaslikelyledtoatrophicmismatchandlowerbreeding successinscoters.

Drever,M.C.,etal.“Populationvulnerabilitytoclimatechangelinkedto timingofbreedinginborealducks.”GlobalChangeBiology18.2(2012): 480-492.

RedPhalarope

InAlaskaredphalaropesnowlaysmallereggsonaverage,presumablydueto lowercondition.Thisislikelyduetodelayedsnowmeltduetohigherprecipitation, despitethegeneralwarmingtrend.AcrossCaliforniaredphalaropeshavedeclined acrosstheirwinteringareas.Thisislikelyduetochangesinoceancurrentsand declinesinpreyabundance.PopulationsaroundAlaskahavedeclinedinsome areas,orpossiblyredistributed,duetochangesinseaiceandinkeycopepodprey species

Gall,A.E.,etal.“Ecologicalshiftfrompiscivoroustoplanktivorousseabirds intheChukchiSea,1975–2012.”PolarBiology40.1(2017):61-78.

Martin,J.-L.,etal."LatesnowmeltcanresultinsmallereggsinArctic shorebirds."PolarBiology41.11(2018):2289-2295.

Sydeman,W.J.,etal.“Climate–ecosystemchangeoffsouthernCalifornia: time-dependentseabirdpredator–preynumericalresponses.”DeepSea ResearchPartII:TopicalStudiesinOceanography112(2015):158-170.

Red-neckedPhalarope

AstudyinAlaskafoundthatphalaropeshavechangedtheirlayingdateinresponse tochangesinsnowmelt.Phalaropeshaverespondedtochangesinoceanic patternsintheIndianoceanandchangedtheirforagingareasandpatternsin response.

Liebezeit,J.R.,etal.“Phenologicaladvancementinarcticbirdspecies: relativeimportanceofsnowmeltandecologicalfactors.”PolarBiology37.9 (2014):1309-1320.

Nussbaumer,R.,etal.“InvestigatingtheinfluenceoftheextremeIndian OceanDipoleonthe2020influxofRed-neckedPhalaropesPhalaropus lobatusinKenya.”Ostrich(2021):1-9.

CommonEider

Knowntobeaffectedbyclimatechangeinotherpartsoftheirrange.Theysuffer increasedpredationfromArcticfoxesduetopreyswitchingfollowingacollapsein lemmingbreedingcyclesinnorthernCanada.InadditionCanadianpopulations havesufferedduetochangesinweatherinthebreedingseason,especially increasedrain,eitherdirectlythroughexposureorindirectlythroughchangesin predation.

Iles,D.T.,etal.“Predators,alternativepreyandclimateinfluenceannual breedingsuccessofalong-livedseaduck.”JournalofAnimalEcology82.3 (2013):683-693.

KingEider

Increaseinicebreak-up,andincreasedvariabilityofbreak-up,causedbyclimate changehasresultedinsignificantdamagetobenthicpreyandhascausedlocal shiftsinpreyavailability.Currentlythishasonlyasmallimpactonkingeiders,but impactscouldbecomesignificantinthefuture.

Lovvorn,J.R.,etal.“LimitstobenthicfeedingbyeidersinavitalArctic migrationcorridorduetolocalizedpreyandchangingseaice.”Progressin Oceanography136(2015):162-174.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,seaducksandphalaropes possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherseaducksandphalaropes haveeither1)Specialisedhabitatand/ormicrohabitatrequirement2)

Environmentaltolerancesorthresholds(atanylifestage)thatarelikelytobe exceededduetoclimatechange3)Dependenceonenvironmentaltriggersthatare likelytobedisruptedbyclimatechange,4)Dependenceoninterspecific interactionsthatarelikelytobedisruptedbyclimatechangeor5)Highrarity.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,seaducksandphalaropes possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherseaducksandphalaropes haveeither:1)Highphenotypicplasticity.2)Highdispersalabilityor3)High evolvability.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Gannetsand Cormorants

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange:

NorthernGannet

1-Gannetsareundertakinglongerforagingtrips,mostlikelyinresponsetoprey shortagesduetoclimatechange.Althoughthislikelyincreasestheenergeticcosts offoraging,therehavesofarbeennoobservedimpactsonbreedingsuccessor mortality.

Davies,R.D.,etal.“Density-dependentforagingandcolonygrowthina pelagicseabirdspeciesundervaryingenvironmentalconditions.”Marine EcologyProgressSeries485(2013):287-294. Gannetsareundertaking longerandlongerforagingtripsCelticandIrishSeas.Thisispresumablydueto foodshortagesclosertothecolony,andclimatechangeislikelyonedriverof this.Coloniesarestillgrowingandexpanding,butataslowertocolonies elsewhereintheUK.Thislikelymeansthesecolonieswillbemoresensitivein futuretoclimatechange,butatthemomentthisisnotclassedasanegative impact.

2-Gannetshaveestablishednewcoloniesaskeypreyspecieshaveshiftedfurther north.

Barrett,R.T.,Strøm,H.,andMelnikov,M.“Onthepolaredge:thestatus ofthenortherngannet(Morusbassanus)intheBarentsSeain2015-16.” PolarResearch36.1(2017):1390384. Since2011gannetshaveestablished coloniesintheBarentsSea(firstonBearIsland),thoughttobeassociatedwith awarmingoftheBarentsSeaandthenorthwardspreadofcommonprey species.

EuropeanShag

1-Shagshaveadvancedtheirlayingdate,mostlikelyduetochangesinmarine andterrestrialtemperaturesandsubsequentlyinpreyavailability Álvarez,D.,andPajuelo,M.A.F."SouthernpopulationsofEuropeanshag Phalacrocoraxa.aristotelisadvancetheirlayingdateinresponsetolocal weatherconditionsbutnottolarge-scaleclimate."Ardeola58.2(2011):

239-250. LayingdatesforshagsinnorthernSpainhavechangeddrastically, advancingbyalmost40daysinonly10years.Thisisincorrelationwithan increaseinlocallandandoceantemperatures,whichisalsothemostlikely reasonbehindthischangeinphenology.

2-Thedietcompositionofshagshaschangedagreatdeal,likelyinresponseto climatechangedrivenchangesinthemarineecosystem

Howells,R.J.,etal.“Pronouncedlong-termtrendsinyear-rounddiet compositionoftheEuropeanshagPhalacrocoraxaristotelis.”MarineBiology 165.12(2018):1-15.Dietcompositionhaschanged,mostlikelyinresponseto climatechange.Noknownimpactonpopulation.StudyontheIsleofMay Howells,R.J.,etal.“Fromdaystodecades:short-andlong-termvariation inenvironmentalconditionsaffectoffspringdietcompositionofamarine toppredator.”MarineEcologyProgressSeries583(2017):227-242. Diet compositionhaschanged,incorrelationtoclimatechangeandchangein sandeelabundance.StudyontheIsleofMay.

3-Extremestormsduringtheshagbreedingseasonhaveledtowide-spreadnest destruction,nestingfailureandanetreductioninannualpopulationproduction Newell,M.,etal.“Effectsofanextremeweathereventonseabirdbreeding successataNorthSeacolony.”MarineEcologyProgressSeries532 (2015):257-268 AsingleextremesummerstormontheIsleofMayresultedin wide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.Whileindividualstormscannotbeeasilybeattributedto climatechange,itisgenerallybelievedthatseverestormsarebecomingmore common

4-Recentdeclinesinshagpopulationsbecauseofhighadultmortalityaremost likelybecauseofincreasinglyseverewinterstorms.

Heubeck,M.,etal.“PopulationandbreedingdynamicsofEuropeanShags PhalacrocoraxaristotelisatthreemajorcoloniesinShetland,2001-15.” Seabird28(2015):55-77. PopulationsintheShetlandshavemarkedly declined,likelyduetohighmortalityfromwinterstorms.Whileindividual extremeweathereventsaredifficulttoattributetoclimatechange,the frequencyandseverityofextremeweathereventsislikelyincreasing.

5-Shagsbreedlateraswintershavebecomecolder

Lorentsen,S.-H.,etal.“Foragefishabundanceisapredictoroftimingof breedingandhatchingbroodsizeinacoastalseabird.”MarineEcology ProgressSeries519(2015):209-220. Medianhatchdatebecamelaterover thestudyperiod(1989–2009).Thiswaspartiallyexplainedbyadeclineinthe

wNAOindex,indicatingcolderconditions.Thisrelationshipwasonlyobservedat oneoftwostudiedcolonies(Røst).Itisuncleariforhowthischangeaffectsthe population

GreatCormorant

1-Cormorantsthatmigratetocoastalareasduringthewinterarenowmigrating later,mostlikelyduetolessandlatericeonfreshwaterfeedingareas. Trella,M.,andWołos,A.."OpinionsofOwnersandManagersofFishing EntitiesinCentralandEasternEuropeontheImpactofClimateChangeon LakeFisheriesManagement."Fisheries&AquaticLife29.4(2021):189201. InPoland,observationalsurveysshowthatcormorantsstaylaterin freshwaterhabitatsduringwinterthanpreviously,duetoshorterice-cover duration.Populationsareshiftingtorelyingmoreheavilyonfreshwater,and awayfromcoastalandmarinehabitats.

2-Cormorantsareexpandingtheirrangeduetoincreasedavailabilityofprey,in largepartduetodeclinesincompetingmarinepredators,whichinturnarepartially drivenbyclimatechange. vanEerden,M.R.,etal.“ExpandingEast:GreatCormorantsPhalacrocorax carboThrivingintheEasternBalticandGulfofFinland.”Ardea109.3 (2022):313-326. Largemarinepredatorshavedeclinedinpartduetoclimate change(inparticularduetowarmerwatersandincreasedeutrophication),along withseveralothermajorfactors,whichhasresultedinanincreaseinsmaller prey.Thisislikelyamajorfactorcontributingtomajorgrowthincormorant populationsinsouthernFinland,Estonia,LithuaniaandacrosstheeasternBaltic area,whicharenowbreedinginareastheywereneverhistoricallyassociated with.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute

resolution.

ForEuropeanshag,andnortherngannetweincludedthefollowingterrestrial variables:Meantemperatureofthewarmestmonth,precipitationduringbreeding season,isolationoflandmass,areaoflandmass,distancetosea.

Forgreatcormorantweincludedthefollowingterrestrialvariables:mean temperatureofthewarmestmonth,precipitationduringbreedingseason,distance tosea.

ForEuropeanshag,andnortherngannetweincludedthefollowingmarine variables:seasurfacetemperature(duringthewinter),salinity,maximum chlorophyllconcentration,bathymetry(depthandvariance).

Severalothervariablesmaystronglyinfluencethedistributionofgannetsand cormorantsanditisnotpossibletoincludeallpossiblevariablesinagivenmodel. Howeverthefollowingvariableshavepreviouslybeenfoundtobeimportantto predictingthedistributionofgannetsandcormorantsinEurope:averagewind speedduringbreedingseason,seasurfaceheight,seabedsubstrate,averagewind speedduringbreedingseason,presenceofstableoceanfronts(orbathymetric proxy)distancetofreshwater,freshwaterdepth,freshwaterph,freshwater chlorophyllconcentration,land“roughness”index.Forlocalassessmentsofclimate change,werecommendthesevariablesarestronglyconsidered.Wehopeto incorporatethesevariablesintofutureversionsofthisguidancedocument.

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2.

Underlyingdataweredownloadedfrom: Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

NorthernGannet keypreyspecies:herring(Clupeaharengus),saithe(Pollachius virens),mackerel(Scomberscombrus),sandeelspecies(Ammodytesmarinus and Ammodytestobianus),capelin(Mallotusvillosus),sprat(Sprattussprattus), haddock(Melanogrammusaeglefinus)andgarfish(Belonebelone).Thisspecieswill alsotakemanyotherspecieswhereavailable,itwillalsoforagefisherydiscards.

Preyspecieslistwascompiledfrom:

LeBot,T.,etal.“Fisherydiscardsdonotcompensatenaturalpreyshortage inNortherngannetsfromtheEnglishChannel.”Biologicalconservation236 (2019):375-384.

Mowbray,T.B.“NorthernGannet(Morusbassanus),version1.0.”InBirds oftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca, NY,USA(2020).

Pettex,E.,etal.“Multi-scaleforagingvariabilityinNortherngannet(Morus bassanus)fuelspotentialforagingplasticity.”MarineBiology159.12 (2012):2743-2756.

EuropeanShag keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),saith(Pollachiusvirens),cod(Gadusmorhua),poorcod (Trisopterusminutus)andcapelin(Mallotusvillosus).Preyspecieslistwascompiled from:

Harris,M.P.,andWanless,S."ThedietofshagsPhalacrocoraxaristotelis duringthechick-rearingperiodassessedbythreemethods."Birdstudy 40.2(1993):135-139.

Hillersøy,G.,andLorentsen,S-H."Annualvariationinthedietofbreeding Europeanshag(Phalacrocoraxaristotelis)inCentralNorway."Waterbirds 35.3(2012):420-429.

Lorentsen,S-H.,Mattisson,J.,andChristensen-Dalsgaard,S. "ReproductivesuccessintheEuropeanshagislinkedtoannualvariationin dietandforagingtripmetrics."MarineEcologyProgressSeries619(2019): 137-147.

GreatCormorant keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),capelin(Mallotusvillosus),flounder(Platichthysflesus), saithe(Pollachiusvirens),seascorpion(Taurulusbubalis),sole(Soleasolea), eelpout(Zoarcesviviparus)andsprat(Sprattussprattus).Thisspeciesalsofeeds onfreshwaterspecies,notablybrowntrout(Salmotrutta),salmonparr,European eel(Anguillaanguilla),roach(Rutilusrutilus),perch(Percafluviatilis)andminnow (Phoxinusphoxinus),butthesewerenotincludedinthisanalysis.Preyspecieslist wascompiledfrom:

Hatch,J.J.,etal.“GreatCormorant(Phalacrocoraxcarbo),version1.0.”In BirdsoftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology, Ithaca,NY,USA(2020).

vanEerden,M.R.,etal.“ExpandingEast:GreatCormorantsPhalacrocorax carboThrivingintheEasternBalticandGulfofFinland.”Ardea109.3 (2022):313-326.

Lehikoinen,A.,Heikinheimo,O.,andLappalainen,A."Temporalchangesin thedietofgreatcormorant(Phalacrocoraxcarbosinensis)onthesouthern coastofFinland-comparisonwithavailablefishdata."Borealenvironment research16(suppl.B)(2011):61–70.

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

NorthernGannet

MarineheatwavesinNorthAmericahaveresultedinwide-spreadbreedingfailure andinsomecasestemporarydesertionofcolonies.Mostlikelybecauseofprey shortages,butheatstresscouldplayaroleaswell.Itisdifficulttoattribute individualclimateeventstoclimatechange,butheatwavesarebecomingmore commonandmoreextreme,andwilllikelycontinuetodoso.Lackofkeyprey species(mackerel)duetowarmeraveragemarinetemperaturesandoverexploitationhascausedlowbreedingsuccessinasouthernpopulationofgannetsin Canada.

Franci,C.D.,etal.“NutritionalstressinNortherngannetsduringan unprecedentedlowreproductivesuccessyear:Canextremeseasurface temperatureeventanddietarychangebethecause?.”Comparative BiochemistryandPhysiologyPartA:Molecular&IntegrativePhysiology181 (2015):1-8

d’Entremont,K.J.N.,etal.“NorthernGannets(Morusbassanus)breeding attheirsouthernlimitstrugglewithpreyshortagesasaresultofwarming waters.”ICESJournalofMarineScience79.1(2022):50-60.

Montevecchi,W.A.,etal.“Oceanheatwaveinducesbreedingfailureatthe southernbreedinglimitoftheNorthernGannetMorusbassanus.”Marine Ornithology49(2021):71-78.

GreatCormorant

CormorantsinGreenlandhavespreadtheirsummerrangefurthernorth,most likelyduetowarmerseatemperaturesandchangesinfoodavailability.However, thishasalsolikelyincreasedthecostsofmigration,ascormorantshavefurtherto traveltoreachice-freeareasinwinter.

White,C.R.,etal.“Energeticconstraintsmaylimitthecapacityofvisually

guidedpredatorstorespondtoArcticwarming.”JournalofZoology289.2 (2013):119-126.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,gannetsandcormorants possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhethergannetsandcormorants haveeither1)Specialisedhabitatand/ormicrohabitatrequirement2)

Environmentaltolerancesorthresholds(atanylifestage)thatarelikelytobe exceededduetoclimatechange3)Dependenceonenvironmentaltriggersthatare likelytobedisruptedbyclimatechange,4)Dependenceoninterspecific interactionsthatarelikelytobedisruptedbyclimatechangeor5)Highrarity. Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,gannetsandcormorants possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhethergannetsandcormorants haveeither:1)Highphenotypicplasticity.2)Highdispersalabilityor3)High evolvability.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Gulls

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange:

EuropeanHerringGull

1-Changesinmercurycycling(duetoincreasedseatemperatures)hasledto increasedexposuretomercury,withnegativeimpactsonherringgullhealth Bełdowska,M.,etal."MercuryconcentrationinthecoastalzoneoftheGulf ofGdanskasafunctionofchangingclimate—preliminaryresults."Baltic SeaScienceCongress:newhorizonsforBalticSeascience.Klaipeda UniversityCORPI,Klaipeda140(2013). Thispaperdoesnotspecifically addressbioaccumulationingulls,butprovidessupportinginformationforthe otherreferencesforthisimpact.Overviewofhowclimatechangecanleadto changesinmercuryconcentrationinBaltic.

Beldowska,M.,etal.“Macrophytaasavectorofcontemporaryand historicalmercuryfromthemarineenvironmenttothetrophicweb.”

EnvironmentalScienceandPollutionResearch22.7(2015):5228-5240. Thispaperdoesnotspecificallyaddressbioaccumulationingulls,butprovides supportinginformationfortheotherreferencesforthisimpact.Overviewofhow mercuryconcentrationintheBalticcyclesintoseabirdtissuesandhowitaffects ecosystemhealth

Saniewska,D.,etal.“Climatechangeanditsimpactonthemercury cyclinginthesouthernBalticSea.”EcosystemdynamicsintheBalticSeain aclimatechangeperspective,03.2015.ConferenceUmeå,Sweden,(2015).

Climatechangeislikelyleadingtoincreasedmercuryconcentrationcyclingin thesouthernBaltic,thisisleadingtohigherconcentrationsofmercuryinherring gulltissues.Whilethishasnotbeenshowntobeaffectingthepopulationinthe Baltic,itisknownthatmercurypoisoningcanseverelyaffectherringgullhealth.

LesserBlack-backedGull

1-Increasedpreyavailabilityduringthebreedingseasonhasledtopopulation growth

Luczak,C.,etal.“NorthSeaecosystemchangefromswimmingcrabsto seagulls.”Biologyletters8.5(2012):821-824. Increasednumbersof swimmingcrabssignificantlycorrelatewithseasurfacetemperatureincreases

andchangesintheabundanceoflesserblack-backedgullsat21majorNorth Seabreedingcolonies(acrossnorthernFranceandBelgium).Thoughnotethere issomedebateonwhetheranincreaseincrabsisactuallythecauseofthe populationincrease.

GlaucousGull

1-Therehasbeenincreasedpredationbypolarbears,mostlikelyduetoreduction inseaiceandthereforealackofalternativeprey.Insomeyearsthishasseverely affectedbreedingsuccess.

Prop,J.,etal.“Climatechangeandtheincreasingimpactofpolarbearson birdpopulations.”FrontiersinEcologyandEvolution3(2015):33. Polar bearsareswappingpreyduetolackofseaiceandpreymoreheavilyon glaucousgulls(amongstotherseabirds).Insomeyearsitseverelyaffects reproductivesuccessinSvalbardandGreenland.

2-Climatechangeislikelycontributingtohigherconcentrationsofcontaminents ingestedbyglaucousgulls.Theoveralleffectonthepopulationisunknown,but presumablynegative.

Alava,J.J.,etal."Climatechange–contaminantinteractionsinmarinefood webs:Towardaconceptualframework."GlobalChangeBiology23.10 (2017):3984-4001. PotentialexacerbationofPOPsandmercuryinmarinefood websduetoclimatechange(i.e.,increasingtemperatures).Glaucousgulls appeartohavehighaccumulationofcompounds,butthere’snoestablished negativeeffectonpopulations.Studywasconductedacrosstheirrange, especiallyaroundGreenland.

3-Climatechangehascontributedtoarangeshiftinseveralhelminthparasites, whichhasledtoglaucousgullsbeingexposedtonovelparasites,aswellas increasedparasiteload.Effectonpopulationisunknown,butpresumablynegative Galaktionov,K.V.“Patternsandprocessesinfluencinghelminthparasitesof Arcticcoastalcommunitiesduringclimatechange.”Journalof Helminthology91.4(2017):387-408. Reviewofhelminthparasitesacrossthe Arctic,especiallyinseabirds.Notesthatseveralparasiteshavebeenrecordedin speciestheyhaveneverbeenassociatedwithbefore.Mostlikelybecauseboreal crustaceansareshiftingnorth,alongwithassociatedparasites.Notablespecies areglaucousgullsandblack-leggedkittiwakeswhichnowhavesignificantnew parasitesatrapidlyincreasingloads.

GreatBlack-backedGull

1-Higherseatemperaturescorrelatewithlowerbreedingsuccess.Mechanism unknown,butlikelymediatedthroughpreyavailability

Burthe,S.J.,etal.“Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts.”MarineEcologyProgressSeries507(2014):277295. Greaterblack-backedgullproductivitydecreasesasseasurface temperaturegetshigher.Probablyduetopreyavailability,studyfocusseson seabirdsinForthandTayregion.

IvoryGull

1-Ivorygullsareheavilyreliantonseaiceforbreedingandhunting,recent decreasesinseaiceareleadingtorapidchangesinpopulationsizeandrange. Gilg,O.,etal.“Livingontheedgeofashrinkinghabitat:theivorygull, Pagophilaeburnea,anendangeredsea-icespecialist.”Biologyletters12.11 (2016):20160277. DemonstrateshowcloselylinkedIvorygullrangesareto seaiceavailabilityacrossitsrange,includingGreenland,Svalbard,Russiaand Canada.Alsonotesthattheirrangeisshrinkingduetochangesinseaice.

2-Asasecondaryimpactofseaiceloss,Ivorygullsfacemorecompetitionfrom otherIvorygullsandfromotherspeciesforresources. Hamilton,C.D.,etal.“SpatialoverlapamonganArcticpredator,preyand scavengerinthemarginalicezone.”MarineEcologyProgressSeries573 (2017):45-59. Decreasingareaofseaicemeanlessareaforivorygulls,polar bearsandringedseals(bothofwhichcommonlyscavengeinsimilarareas).This leadstoincreasedintra-andinter-specificcompetition.

Black-leggedKittiwake

1-Decreasedpreyavailabilityduetowarmerseashasledtolowerbreeding success

Sandvik,H.,etal.“ThedeclineofNorwegiankittiwakepopulations: modellingtheroleofoceanwarming.”ClimateResearch60.2(2014):91102. Thestudyfindacorrelationbetweenlowerbreedingsuccessandsea surfacetemperaturealongNorwegiancoast.Thesuggestedmechanismis throughpreyavailabilityasthisisknowntoaffectbreedingsuccessinvarious partsoftheirrange.

2-Kittiwakediethaschangedsignificantlyduetoclimate-changedrivenshiftin preyassemblage.However,sofarthishasnotresultedinanydemonstrated changeinbreedingsuccess.

Vihtakari,M.,etal.“Black-leggedkittiwakesasmessengersof AtlantificationintheArctic.”ScientificReports8.1(2018):1-11. Kittiwake dietinSvalbardchangedsignificantlyovera10-yearperiod(2006-2016),from predominantlyArcticspeciestospeciesmoreassociatedwithwarmerAtlantic

waters,incorrelationwithincreaseinoceantemperatureandlossofseaice. Therewere,however,nosignificantchangesinclutchsizeorbreedingsuccess duringthistime.

3-Kittiwakepopulationshaveshiftedtheirrangeinresponsetochangesin distributionofkeypreyspecies.

Garðarsson,A.,Guðmundsson,G.A.,andLilliendahl,K."Framvinda íslenskraritubyggða."Bliki32(2013):1-10. Kittiwakeshaveredistributed acrossIceland.Populationsinthenorthhavedecreased,andpopulationsinthe westhaveincreased.Thepopulationingeneralisrelativelystable.Theauthors hypothesisethisislikelyduetoredistributionofcapelin,akeypreyspeciesof kittiwakesinIceland.

4-Climatechangehascontributedtoarangeshiftinseveralhelminthparasites, whichhasledtokittiwakesbeingexposedtonovelparasites,aswellasincreased parasiteload.Effectonpopulationisunknown,butmostlikelynegative Galaktionov,K.V.“Patternsandprocessesinfluencinghelminthparasitesof Arcticcoastalcommunitiesduringclimatechange.”Journalof Helminthology91.4(2017):387-408. Reviewofhelminthparasitesacrossthe Arctic,especiallyinseabirds.Notesthatseveralparasiteshavebeenrecordedin speciestheyhaveneverbeenassociatedwithbefore.Mostlikelybecauseboreal crustaceansareshiftingnorth,alongwithassociatedparasites.Notablespecies areglaucousgullsandblack-leggedkittiwakeswhichnowhavesignificantnew parasitesatrapidlyincreasingloads.

5-Higherseatemperaturescorrelatewithlowerbreedingsuccess.Mechanism unknown,butpotentiallymediatedthroughpreyavailability.Alternativetheories suggestfisherypressurehasbeenalargecontributingfactor.

Burthe,S.J.,etal.“Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts.”MarineEcologyProgressSeries507(2014):277295. Kittiwakeproductivityhasdecreasedasseasurfacetemperaturehas increased.Probablyduetopreyavailability,studyfocussesonseabirdsinForth andTayregion.

Carroll,M.J.,etal.“Effectsofseatemperatureandstratificationchanges onseabirdbreedingsuccess.”ClimateResearch66.1(2015):75-89. Across 11coloniesintheUKandIreland,kittiwakebreedingsuccesswaslowerinyears withhigherspringseasurfacetemperatures(andstrongoceanstratificationin theprecedingwinter).Bothvariablesincreasedoverthestudyperiod.However, keydriversofproductivityvariedbetweencolonies.Environmentalvariables

weretakenfromtheobservedforagingareasofthekittiwakes.Thestudy suggestsafood-web-basedmechanismforimpact.

Frederiksen,M.,etal.“Regionalandannualvariationinblack-legged kittiwakebreedingproductivityisrelatedtoseasurfacetemperature.” MarineEcologyProgressSeries350(2007):137-143. Overthestudyperiod (mid-1980stomid-2000s,February/Marchseasurfacetemperatureincreased aroundsixofsixcoloniesintheUKandIreland–althoughonlysignificantlyso intwo.BreedingproductivitynegativelyrelatedtoSSTacrossallcolonies,and fortwoofsixindividualcolonies.Thestudysuggeststhemechanismisunclear, butlikelyoperatesthrougheffectsonsandeels.

6-Kittiwakecolonieshavedeclinedduringperiodsofrapidoceanwarming. Mechanismunknown,butlikelyduetorapidchangesinmarineecosystemsand preyavailability

Descamps,S.,etal.“Circumpolardynamicsofamarinetop-predatortrack oceanwarmingrates.”GlobalChangeBiology23.9(2017):3770-3780. RapidincreasesinSSTaroundcircumpolarkittiwakecoloniesinthe1990s conicidedwithsteepdeclinesincolonysize.Thesuggestedmechanismisabrupt “regimeshifts”thatchangedpreyavailability.

7-Extremestormsduringthenon-breedingseasonhaveledtomassmortalityof kittiwakes(‘wrecks’)

Clairbaux,M.,etal.“NorthAtlanticwintercyclonesstarveseabirds.” CurrentBiology31.17(2021):3964-3971. Followingheavystormaction, seabirdmortalityincreasesduetoincreaseddifficultyforaging(ratherthan increasedenergeticcosts).Theauthorsuseamulti-speciesdataset(puffins, littleauks,commonmurres,andthick-billedmurres)overawideareaofthe Atlanticbasin.TheyconcludethatseabirdsaroundIcelandandtheBarentsSea (alongwithseveralN.Americansites)areparticularlyvulnerable.Climate changeislikelytobeacontributingfactortopresentandfuturestormmortality.

8-Extremestormsduringthekittiwakebreedingseasonhaveledtowide-spread nestdestruction,nestingfailureandanetreductioninannualpopulationproduction Newell,M.,etal.“Effectsofanextremeweathereventonseabirdbreeding successataNorthSeacolony.”MarineEcologyProgressSeries532 (2015):257-268. AsingleextremesummerstormontheIsleofMayresulted inwide-spreadnestdestruction,nestingfailureandanetreductioninannual populationproduction.Whileindividualstormscannotbeeasilybeattributedto climatechange,itisgenerallybelievedthatseverestormsarebecomingmore common.

Yellow-leggedGull

1-Changesinpreyavailabilityhavecausedspeciestoswapprey Calado,J.G.,etal.“Anthropogenicfoodresources,sardinedeclineand environmentalconditionshavetriggeredadietaryshiftofanopportunistic seabirdoverthelast30yearsonthenorthwestcoastofSpain.”Regional EnvironmentalChange20.1(2020):1-13. Yellow-leggedgullshavechanged theirdietfollowingdeclinesinsardinepopulations,drivenbyclimatechangeand fisheryactivity.Studybasedonseveralpopulationsonthenorth-westcoastof Spain.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

ForEuropeanherringgull,Audouin’sgull,lesserblack-backedgull,glaucousgull, greatblack-backedgull,ivorygull,black-leggedkittiwake,andSabine’sgullwe includedthefollowingterrestrialvariables:Meantemperatureofthewarmest month,precipitationduringbreedingseason,isolationoflandmass,areaof landmass,distancetosea

ForCaspiangull,andyellow-leggedgullweincludedthefollowingterrestrial variables:meantemperatureofthewarmestmonth,precipitationduringbreeding season,distancetosea.

ForAudouin’sgull,lesserblack-backedgull,glaucousgull,greatblack-backedgull, ivorygull,black-leggedkittiwake,andSabine’sgullweincludedthefollowing marinevariables:seasurfacetemperature(duringthewinter),salinity,maximum chlorophyllconcentration,bathymetry(depthandvariance).

Severalothervariablesmaystronglyinfluencethedistributionofgullsanditisnot possibletoincludeallpossiblevariablesinagivenmodel.Howeverthefollowing

variableshavepreviouslybeenfoundtobeimportanttopredictingthedistribution ofgullsinEurope:sealevelheight.Forlocalassessmentsofclimatechange,we recommendthesevariablesarestronglyconsidered.Wehopetoincorporatethese variablesintofutureversionsofthisguidancedocument.

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2. Underlyingdataweredownloadedfrom:

Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata.

Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe

currentforagingrangeagivenspecies,wemarkedthisonthesummarymap. Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

EuropeanHerringGull keypreyspecies:Thisspecieshasaveryvarieddiet, includingincludingfish,discards,bivalves,gastropods,crustaceans,squid,insects, refuseandotherseabirds,amongmanyotherfoodsources.Nokeyspecieswere identified,sothekeypreyassessmentisnotcomplete

Audouin’sGull keypreyspecies:sardines(Sardinapilchardus),Atlanticsaury (Scomberesoxsaurus)andbluewhiting(Micromesistiuspoutassou).Thisspeciesis alsoknowntofeedonvariousotherdemersalandpelagicfish,aswellasvarious terrestrialfoodsources,butnootherspeciescouldbefirmlyidentifiedaskeyprey species.Preyspecieslistwascompiledfrom:

Burger,J.,etal.“Audouin’sGull(Ichthyaetusaudouinii),version1.0.”In BirdsoftheWorld(J.delHoyo,A.Elliott,J.Sargatal,D.A.Christie,andE. deJuana,Editors).CornellLabofOrnithology,Ithaca,NY,USA(2020)

Calado,J.G.,etal.“Seasonalandannualdifferencesintheforaging ecologyoftwogullspeciesbreedinginsympatryandtheiruseoffishery discards.”JournalofAvianBiology49.1(2018).

CaspianGull keypreyspecies:Thisspecieshasavarieddietofinvertebrates.No keyspecieswereidentifiedandsothekeypreyassessmentisnotcomplete LesserBlack-backedGull keypreyspecies:herring(Clupeaharengus),saithe (Pollachiusvirens)andsandeelspecies(Ammodytesmarinus and Ammodytes tobianus).Manypopulationsalsorelyheavilyondiscards,refuseandegg/chick predation.Thesefoodsourceswerenotincludedinthisassessment.Preyspecies listwascompiledfrom:

Burger,J.,etal.“LesserBlack-backedGull(Larusfuscus),version1.0.”In BirdsoftheWorld(J.delHoyo,A.Elliott,J.Sargatal,D.A.Christie,andE. deJuana,Editors).CornellLabofOrnithology,Ithaca,NY,USA(2020).

Bustnes,J.O.,Barrett,R.T.,andHelberg,M."NorthernLesserBlackBackedGulls:WhatdoTheyEat?."Waterbirds33.4(2010):534-540.

GlaucousGull keypreyspecies:Arcticcod(Boreogadussaida),cod(Gadus morhua),sandeelspecies(Ammodytesmarinus and Ammodytestobianus),capelin (Mallotusvillosus)andherring(Clupeaharengus).Preyspecieslistwascompiled from:

Weiser,E.andGilchrist,H.G.“GlaucousGull(Larushyperboreus),version 1.0.”InBirdsoftheWorld(S.M.Billerman,Editor).CornellLabof Ornithology,Ithaca,NY,USA(2020).

GreatBlack-backedGull keypreyspecies:capelin(Mallotusvillosus),cod (Gadus morhua),mackerel(Scomberscombrus)andherring(Clupeaharengus).Some populationsalsorelyonotherseabirds(includingeggs,chicksandadults)asan importantpreysource.Thesewerenotincludedinthekeypreyassessment.Prey specieslistwascompiledfrom:

Good,T.P.“GreatBlack-backedGull(Larusmarinus),version1.0.”InBirds oftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca, NY,USA(2020).

IvoryGull keypreyspecies:Arcticcod(Boreogadussaida).Thisspeciesalsopreys frequentlyoninvertebratesandotherfish,howeverthesewerenotincludedinthe assessment.Preyspecieslistwascompiledfrom:

Mallory,M.L.,etal.“IvoryGull(Pagophilaeburnea),version1.0.”InBirds oftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca, NY,USA(2020).

Black-leggedKittiwake keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),sprat(Sprattussprattus),Arcticcod(Boreogadus saida),capelin(Mallotusvillosus)andherring(Clupeaharengus).Preyspecieslist wascompiledfrom:

Hatch,S.A.,Robertson,G.J.,andBaird,P.H.“Black-leggedKittiwake (Rissatridactyla),version1.0.”InBirdsoftheWorld(S.M.Billerman, Editor).CornellLabofOrnithology,Ithaca,NY,USA(2020).

Fauchald,Per,etal."ThestatusandtrendsofseabirdsbreedinginNorway andSvalbard."NINArapport1151.Norskinstituttfornaturforskning (2015):1-84.

JohansenM.,etal."InternationalBlack-leggedKittiwakeConservation StrategyandActionPlan"CircumpolarSeabirdExpertGroup.Conservation ofArcticFloraandFauna,Akureyri,Iceland(2020).

Sabine’sGullkeypreyspecies:Thisspecieshasavarieddietofinvertebratesand fish.Nokeyspecieswereidentifiedandsothekeypreyassessmentisnot complete

Yellow-leggedGull keypreyspecies:Henslow’sswimmingcrab(Polybius henslowii),sardines(Sardinapilchardus),chubmackeral(Scombercolias),blue whiting(Micromesistiuspoutassou)andhake(Merlucciusmerluccius).Thisspecies hasavarieddietofpelagicanddemersalfish,aswellasseveralterrestrialfood sources.Notethatseveralofthefishspeciesheremaybefromfisherydiscards.

Preyspecieslistwascompiledfrom:

delHoyo,J.,etal.“Yellow-leggedGull(Larusmichahellis),version1.0.”In BirdsoftheWorld(J.delHoyo,A.Elliott,J.Sargatal,D.A.Christie,andE. deJuana,Editors).CornellLabofOrnithology,Ithaca,NY,USA(2020). Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

EuropeanHerringGull

Increasedfloodingduetosealevelrisehasledtothereductionordestructionof severalpopulationsintheUS.

Burger,J.,andGochfeld,M."Habitat,populationdynamics,andmetal levelsincolonialwaterbirds:afoodchainapproach."CRCPres,NewYork (2016).

GlaucousGull

Glaucousgullcoloniesdisplayhigherratesofcannabalismandlowerbreeding successinresponsetohigherseatemperatures.Thisispresumablyduetolackof marineprey,andislikelytobeexcerabatedwithfurtherclimatechange.

Hayward,J.L.,etal.“Eggcannibalisminagullcolonyincreaseswithsea surfacetemperature.”TheCondor116.1(2014):62-73.

IvoryGull

Climatechangeisknowntohaveseveralotherimpactsinotherpartsofthespecies

range,inparticularthroughchangingwinterfoodsupplies,increasingcompetition withothermarinebirds,andincreasedpredationduetoincreasedaccessto previouslyisolatedcolonies.

Gilchrist,H.G.,andMallory,M.L."Declinesinabundanceanddistribution oftheivorygull(Pagophilaeburnea)inArcticCanada."Biological Conservation121.2(2005):303-309.

Hamilton,C.D.,etal.“SpatialoverlapamonganArcticpredator,preyand scavengerinthemarginalicezone.”MarineEcologyProgressSeries573 (2017):45-59.

Yannic,G.,etal.“Completebreedingfailuresinivorygullfollowingunusual rainystormsinNorthGreenland.”PolarResearch33.1(2014):22749.

Black-leggedKittiwake

RecentheatwavesintheNorthPacifichaveresultedinmassmortalityandwidespreadbreedingfailureatkittiwakecolonies

JohansenM.,etal."InternationalBlack-leggedKittiwakeConservation StrategyandActionPlan"CircumpolarSeabirdExpertGroup.Conservation ofArcticFloraandFauna,Akureyri,Iceland(2020). Note:datanotprovided inreport.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,gullspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhethergullshaveeither1)Specialisedhabitat and/ormicrohabitatrequirement2)Environmentaltolerancesorthresholds(atany lifestage)thatarelikelytobeexceededduetoclimatechange3)Dependenceon environmentaltriggersthatarelikelytobedisruptedbyclimatechange,4) Dependenceoninterspecificinteractionsthatarelikelytobedisruptedbyclimate changeor5)Highrarity.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,gullspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhethergullshaveeither:1)Highphenotypic plasticity.2)Highdispersalabilityor3)Highevolvability.

Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Loons/Diversand Grebes

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange: NoimpactswererecordedforLoons/DiversandGrebesinEurope

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

ForArcticloon,commonloon,hornedgrebe,andred-neckedgrebeweincludedthe followingterrestrialvariables:Meantemperatureofthewarmestmonth, precipitationduringbreedingseason,distancetosea

Forred-throatedloonweincludedthefollowingterrestrialvariables:Mean temperatureofthewarmestmonth,precipitationduringbreedingseason,isolation oflandmass,areaoflandmass,distancetosea

Nomarinevariableswereincludedforthisspeciesgroup,astheyare predominantlyterrestrialduringthebreedingseason.

Severalothervariablesmaystronglyinfluencethedistributionofloons,diversand grebesanditisnotpossibletoincludeallpossiblevariablesinagivenmodel. Howeverthefollowingvariableshavepreviouslybeenfoundtobeimportantto predictingthedistributionofloons,diversandgrebesinEurope:distancetofresh water,freshwaterdepth,freshwaterph,freshwaterchlorophyllconcentration,land

“roughness”index.Forlocalassessmentsofclimatechange,werecommendthese variablesarestronglyconsidered.Wehopetoincorporatethesevariablesinto futureversionsofthisguidancedocument.

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2. Underlyingdataweredownloadedfrom:

Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

ArcticLoon keypreyspecies:herring(Clupeaharengus),sprat(Sprattussprattus) andcod(Gadusmorhua).Thisspecieswillalsopreyonfreshwaterfish,especially duringthebreedingseason,notablysalmonids,perch,roach,minnowsand sticklebacks.However,freshwaterspecieswerenotincludedinthekeyprey assessment.Preyspecieslistwascompiledfrom:

Jackson,D.B."Environmentalcorrelatesoflakeoccupancyandchick survivalofblack-throateddiversGaviaarcticainScotland."BirdStudy52.3 (2005):225-236.

Russell,R.W.“ArcticLoon(Gaviaarctica),version1.0.”InBirdsofthe World(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca,NY,USA (2020).

Söderlund,E.Effectsofwhitefishspeciationonpiscivorousbirds.Adietary studyofpiscivorousbirdsincentralandnorthernSweden.UmeåUniversity (2021).MScThesis.

CommonLoon keypreyspecies:Duringthebreedingseasonthisspeciespreys primarilyonsalmonids.However,freshwaterspeciesarenotassessedaspartof thekeypreyassessment.Alsofeedsonawidevarietyofmarinespecies,however nokeypreyspecieswereidentified.Currentlythereisnokeypreyassessmentfor thisspecies

Red-throatedLoon keypreyspecies:herring(Clupeaharengus),sprat(Sprattus sprattus),sandeels(Ammodytesmarinus),cod(Gadusmorhua)andsmelt (Osmeruseperlanus).Thisspeciesalsocommonlypreysonfreshwaterfish, especiallyduringthebreedingseason,howeverthesewerenotincludedinthekey preyassessment.Preyspecieslistwascompiledfrom:

Eriksson,M.O.G.,andPaltto,H."Vattenkemiochfiskbeståndens sammansättningistorlommensGaviaarcticahäckningssjöar,samten jämförelsemedsmålommensGaviastellatafiskesjöar."OrnisSvecica20.1 (2010):3-30.

Rizzolo,D.J.,etal.“Red-throatedLoon(Gaviastellata),version2.0.”In

BirdsoftheWorld(P.G.RodewaldandB.K.Keeney,Editors).CornellLab ofOrnithology,Ithaca,NY,USA(2020).

HornedGrebe keypreyspecies:three-spinedsticklebacks(Gasterosteus aculeatus)andsmelt(Osmeruseperlanus).Thisspeciesalsopreysonsmallaquatic andairbornearthropods,particularlyduringthebreedingseason(beetles, dragonfliesanddamselflies,mayfliesetc.).Invertebratesarenotcurrentlyincluded inkeypreyassessments.Whilethisspeciesdoespreyonotherfishspecies,none wereidentifiedaskeyspeciessowerenotincluded.Preyspecieslistwascompiled from:

Dillon,I.A.,Hancock,M.H.,andSummers,R.W."Provisioningof SlavonianGrebePodicepsaurituschicksatnestsinScotland."BirdStudy 57.4(2010):563-567.

Piersma,T.“Bodysize,nutrientreservesanddietofRed-neckedand SlavonianGrebesPodicepsgrisegenaandP.auritusonLakeIJsselmeer, TheNetherlands.”BirdStudy35.1(1988):13-24.

Sonntag,N.,Garthe,S.,andAdler,S."Afreshwaterspecieswinteringina brackishenvironment:HabitatselectionanddietofSlavoniangrebesinthe southernBalticSea."Estuarine,CoastalandShelfScience84.2(2009): 186-194.

Stedman,S.J.(2020).“HornedGrebe(Podicepsauritus),version1.0.”In BirdsoftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology, Ithaca,NY,USA(2020).

Red-neckedGrebe keypreyspecies:Smelt(Osmeruseperlanus),pilchard (Gasterosteusaculeatus),three-spinedstickleback(Crangoncrangon)andprawns. Thisspeciesfeedsonvariousfishandinvertebrates,includingmanyfreshwater species(dragonflyandcaddisflylarvaeamongmanyothers).Freshwaterspecies werenotincludedinthekeypreyassessment.Preyspecieslistwascompiledfrom: Stout,B.E.andNuechterlein,G.L.“Red-neckedGrebe(Podiceps grisegena),version1.0.”InBirdsoftheWorld(S.M.Billerman,Editor). CornellLabofOrnithology,Ithaca,NY,USA(2020).

Piersma,T.“Bodysize,nutrientreservesanddietofRed-neckedand SlavonianGrebesPodicepsgrisegenaandP.auritusonLakeIJsselmeer, TheNetherlands.”BirdStudy35.1(1988):13-24.

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic

species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

CommonLoon

SeveralimpactsofclimatechangehavebeennotedinNorthAmericanpopulations, includingdecreasedbroodsize,changesinmigrationpatterns,increasedenergetic stressduetohighertemperatures,andanincreaseinexposuretomercury.

Paruk,J.D.,etal.“CommonLoon(Gaviaimmer),version2.0.”InBirdsof theWorld(P.G.RodewaldandB.K.Keeney,Editors).CornellLabof Ornithology,Ithaca,NY,USA(2021).

Bianchini,K.,etal.“DriversofdeclinesinCommonLoon(Gaviaimmer) productivityinOntario,Canada.”ScienceoftheTotalEnvironment738 (2020):139724.

Red-throatedLoon

Red-throatedLoonbeencausedby“redtides”(massgrowthofredalgae).Itis difficulttoattributeoneeventtoclimatechange,butredtideshavebecomemore commonandmorewidespreadinCaliforniaandglobally,whichhasbeenlinkedto theeffectsofclimatechange.

Jessup,D.A.,etal.“Massstrandingofmarinebirdscausedbya surfactant-producingredtide.”PLoSOne4.2(2009):e4550.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,loons,diversandgrebes possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherloons,diversandgrebes haveeither1)Specialisedhabitatand/ormicrohabitatrequirement2)

Environmentaltolerancesorthresholds(atanylifestage)thatarelikelytobe exceededduetoclimatechange3)Dependenceonenvironmentaltriggersthatare likelytobedisruptedbyclimatechange,4)Dependenceoninterspecific interactionsthatarelikelytobedisruptedbyclimatechangeor5)Highrarity.

Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,loons,diversandgrebes possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherloons,diversandgrebes haveeither:1)Highphenotypicplasticity.2)Highdispersalabilityor3)High evolvability.

Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Petrelsand Shearwaters

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange:

Cory’sShearwater

1-Newcolonieshavebeenestablishedoutsideofthespecies’normalrange.The causeisuncertain,butlikelyrelatedtopreyrangeshiftsandwarmingconditions.

Munilla,Ignacio,etal.“Colonyfoundationinanoceanicseabird.”PloSone 11.2(2016):e0147222. Cory’sshearwatershaveestablishedseveralbreeding coloniesinGalicia,anareatheyhaveneverhistoricallybeenassociatedwith. Theauthorsnotethisisarareevent,as,likemostshearwaters,Cory’s shearwatershavehighsitefidelity.Thecauseisunknown,buttheauthors hypothesistheunderlyingcauseisgenerallywarmingconditionandshiftof warm-waterpreyspeciesnorth.

NorthernFulmar

1-Warmerwintershaveresultedinloweradultsurvivalandlowerreproductive successinthefollowingyear.Mechanismunknown,potentiallycouldberelatedto marineproductivity

Grosbois,V.,andThompson,P.M.."NorthAtlanticclimatevariation influencessurvivalinadultfulmars."Oikos109.2(2005):273-290. Adult survivaldecreasedoverthestudyperiod,incorrelationwithwinterclimate conditions(WNAO).Mechanismunknown.StudyinEynhallow,Orkneys. Lewis,S.,etal.“Effectsofextrinsicandintrinsicfactorsonbreeding successinalonglivedseabird.”Oikos118.4(2009):521-528. Confirmsthe formerusingdatafromthesamepopulation(Eynhallow,Orkneys).Effectsof NAO(andincreasedwinterSST)haveanegative,laggedimpactonfulmar breedingsuccess.

2-Higherseatemperaturestypicallycorrelatewithlowerbreedingsuccess. Mechanismunknown,butlikelymediatedthroughpreyavailability.Continued warmingmaycauselong-termdeclinesinpopulations.

Burthe,S.J.,etal.“Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts.”MarineEcologyProgressSeries507(2014):277-

295. Fulmarproductivitydecreasesasseasurfacetemperaturegetshigher. Probablyduetopreyavailability,studyfocussesonseabirdsinForthandTay region.

EuropeanStorm-petrel

1-Highwindsandstormsinthenon-breedingseasoncausesincreasedmortality, lowerbodycondition,andreducedbreedingsuccess.Whileindividualextreme climateeventsaredifficulttoattributetoclimatechange, itislikelythatclimate changeisdrivinganincreaseintheirfrequencyand/orintensity.

Zuberogoitia,I.,etal.“Assessingtheimpactofextremeadverseweather onthebiologicaltraitsofaEuropeanstormpetrelcolony.”Population ecology58.2(2016):303-313. Reproductivebreedingsuccesswaslower, moultingoccurredlaterandmoreskippedbreedingoccurredinyearsfollowinga winterwithadverseweather.Protractedperiodsofcontinuousgale-forcewinds preventspetrelsfromfeeding,andtheybecomeexhaustedandseverely weakened.StudywasinAketxcolony(Biscay,northofSpain).

2-Ashifttowardswarmer,drierandcalmerconditionshasresultedinlowerstorm petrelabundance.Themechanismisunknown,butlikelyrelatedtochangesin marineecosystemandkeypreyavailability.

Hemery,G.,etal.“Detectingtheimpactofoceano-climaticchangeson marineecosystemsusingamultivariateindex:thecaseoftheBayof Biscay(NorthAtlantic-EuropeanOcean).”GlobalChangeBiology14.1 (2008):27-38. AbundanceofEuropeanstorm-petrelsintheBayofBiscay declinedfrom1974to2000.Thenumberofbreedingpairsperyearwas negativelycorrelatedwithalocalmultivariateclimateindex(combining11 oceanicandatmosphericvariables).Stormpetrelsseemtohavesufferedlocally fromatrendtowardswarmer,drieryearswithcalmerseasurfaceconditions.

ManxShearwater

1-Reducedpreyavailabilityduringthebreedingseasonhasledtolongerforaging tripsandlowerconditioninadultsandchicks

Riou,S.,etal.“Recentimpactsofanthropogenicclimatechangeona highermarinepredatorinwesternBritain.”MarineEcologyProgressSeries 422(2011):105-112. Inwarmeryears,preyislessavailableandadultsmust foragefurthertofindprey.Asaresult,adultsbreedlaterandchicksreachlower peakandfledglingstatus.StudyconductedonSkomerIslandoverseveral breedingseasons.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring

thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

ForCory’sshearwater,northernfulmar,band-rumpedstorm-petrel,Leach’sstormpetrel,Europeanstorm-petrel,andManxshearwaterweincludedthefollowing terrestrialvariables:meantemperatureofthewarmestmonth,precipitationduring breedingseason,isolationoflandmass,areaoflandmass,distancetosea.

ForCory’sshearwater,northernfulmar,band-rumpedstorm-petrel,Leach’sstormpetrel,Europeanstorm-petrel,andManxshearwaterweincludedthefollowing marinevariables:seasurfacetemperature(duringthewinter),salinity,maximum chlorophyllconcentration,bathymetry(depthandvariance).

Severalothervariablesmaystronglyinfluencethedistributionofpetrelsand shearwatersanditisnotpossibletoincludeallpossiblevariablesinagivenmodel. Howeverthefollowingvariableshavepreviouslybeenfoundtobeimportantto predictingthedistributionofpetrelsandshearwatersinEurope:averagewind speedduringbreedingseason,presenceofstableoceanfronts(orbathymetric proxy).Forlocalassessmentsofclimatechange,werecommendthesevariables arestronglyconsidered.Wehopetoincorporatethesevariablesintofutureversions ofthisguidancedocument.

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman

behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2.

Underlyingdataweredownloadedfrom:

Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies. Cory’sShearwater keypreyspecies:saury(Scombresoxsaurus),chubmackerel (Scombercolias),sardines(Sardinapilchardus)andgarfish(Belonebelone).This speciesalsopreysfrequentlyoncephalopodsandotherfish,howeverthesewere notincludedintheassessment.Preyspecieslistwascompiledfrom: Alonso,H.,etal."Parent–offspringdietarysegregationofCory’s shearwatersbreedingincontrastingenvironments."MarineBiology159.6

(2012):1197-1207.

NorthernFulmar keypreyspecies:Atlanticcod(Mallotusvillosus),sandeelspecies (Ammodytesmarinus and Ammodytestobianus),herring(Clupeaharengus), Norwaypout(Trisopterusesmarkii),whiting(Merlangiusmerlangus),squid (Gonatusfabricii)andcrustaceans.Thisspeciesalsoheavilypreysonvarious crustaceanandcephalopodspecies,aswellasfisherydiscards.Howevercurrently thesearenotincludedinthekeypreyassessment.Preyspecieslistwascompiled from:

Phillips,R.A.,etal.“DietofthenorthernfulmarFulmarusglacialis: relianceoncommercialfisheries?.”MarineBiology135.1(1999):159-170. Mallory,M.L.,Hatch,S.A.,AndNettleship,D.N.“NorthernFulmar (Fulmarusglacialis),version1.0.”InBirdsoftheWorld(S.M.Billerman, Editor).CornellLabofOrnithology,Ithaca,NY,USA(2020).

Band-rumpedStorm-petrel keypreyspecies:bluewhiting(Micromesistius poutassou)andpoorcod(Trisopterusminutus alongwithother Trisopterus sp.). ThedietofthisspeciesispoorlycharacterisedinEurope,itmayhaveotherkey preyspeciesthathaveyettobeidentified,andmayinadditionrelyondiscardsin somepopulations.Preyspecieslistwascompiledfrom:

Carreiro,A.R.,etal.“Metabarcoding,stablesisotopes,andtracking: unravelingthetrophicecologyofawinter-breedingstormpetrel (Hydrobatescastro)withamultimethodapproach.”MarineBiology167.2 (2020):1-13.

Leach’sStorm-petrel keypreyspecies:glacierlanternfish(Benthosemaglaciale) andArctictelescope(Protomyctophumarcticum).Preyspecieslistwascompiled from: Hedd,A.,andMontevecchi,W.A."DietandtrophicpositionofLeach’s storm-petrelOceanodromaleucorhoaduringbreedingandmoult,inferred fromstableisotopeanalysisoffeathers."MarineEcologyProgressSeries 322(2006):291-301.

EuropeanStorm-petrel keypreyspecies:sprat(Sprattussprattus)andsandeels (Ammodytesmarinus).Thisspeciescommonlypreysoncrustaceans,zooplankton andothermarineinvertebrates,theseareamajorcomponentofdietinmany populations.However,presentlythesespeciesarenotincludedinthekeyprey assessment.Preyspecieslistwascompiledfrom:

Carboneras,C.,Jutglar,F.,andKirwan(2021),G.M.“EuropeanStorm-

Petrel(Hydrobatespelagicus),version1.1.”InBirdsoftheWorld(Editor notavailable).CornellLabofOrnithology,Ithaca,NY,USA(2020)

D'Elbee,J.,andHemery,G."DietandforagingbehaviouroftheBritish StormPetrelHydrobatespelagicusintheBayofBiscayduringsummer." Ardea86.1(1998):1-10.

ManxShearwater keypreyspecies:herring(Clupeaharengus),sprat(Sprattus sprattus),sardines(Sardinapilchardus),anchovies(Engraulisencrasicolus)and sandeels(Ammodytesmarinus).Thisspeciesalsoheavilypreysoncephalopod species,howeverthesearepoorlycharacterisedsowerenotincludedinthis analysis.Preyspecieslistwascompiledfrom:

Riou,S.,etal.“Recentimpactsofanthropogenicclimatechangeona highermarinepredatorinwesternBritain.”MarineEcologyProgressSeries 422(2011):105-112.

Lee,D.S.,etal.“ManxShearwater(Puffinuspuffinus),version1.0.”In BirdsoftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology, Ithaca,NY,USA(2020).

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

Leach’sStorm-petrel

Leach’sstorm-petrelsinNorthAmericahavechangedtheirpreyspeciesand foragingstrategyinresponsetoshiftsinthemarineecosystempartiallydrivenby climatechange.HeatwavesinNorthAmericahaveimpactedstorm-petrelcolonies andresultedinchangesindiet,lossofconditionandwrecks.Whileindividual heatwavesaredifficulttoattributetoclimatechange,itislikelythefrequencyand intensityofsucheventsisincreasing.Leach’sstorm-petrelreproductivesuccessin Canadahasbeenlinkedtoglobaltemperature.Warmertemperaturesresultin higherreproductivesuccess,upuntilacertainthresholdafterwhichitdecreases. Themechanismisunknown.

Hedd,A.,etal.“DietsanddistributionsofLeach’sstorm-petrel (Oceanodromaleucorhoa)beforeandafteranecosystemshiftinthe NorthwestAtlantic.”CanadianJournalofZoology87.9(2009):787-801. D’Entremont,K.,etal.“On-landforagingbyLeach’sStormPetrels Oceanodromaleucorhoacoincideswithanomalousweatherconditions.” MarineOrnithology49(2021):247-252.

Mauck,R.A.,Dearborn,D.C.,andHuntington,C.E."Annualglobalmean temperatureexplainsreproductivesuccessinamarinevertebratefrom 1955to2010."GlobalChangeBiology24.4(2018):1599-1613.

ManxShearwater

Manxshearwatersareknowntobesensitivetoclimatechangeinthetropics, particularlytowreckscausedbystorms,whicharebecomingmorecommondueto changesintheElNinocycle

Tavares,D.C.,etal.“Mortalityofseabirdsmigratingacrossthetropical Atlanticinrelationtooceanographicprocesses.”AnimalConservation23.3 (2020):307-319

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,petrelsandshearwaters possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherpetrelsandshearwaters haveeither1)Specialisedhabitatand/ormicrohabitatrequirement2)

Environmentaltolerancesorthresholds(atanylifestage)thatarelikelytobe exceededduetoclimatechange3)Dependenceonenvironmentaltriggersthatare likelytobedisruptedbyclimatechange,4)Dependenceoninterspecific interactionsthatarelikelytobedisruptedbyclimatechangeor5)Highrarity.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that

indicateadaptivecapacityandidentifiedwhich,ifany,petrelsandshearwaters possessed.Inbrief,weconsultedpublishedliteratureaswellasexpertknowledge andonlinedatabasessuchasBirdlife(http://datazone.birdlife.org/)andBirdsofthe World(https://birdsoftheworld.org),toassesswhetherpetrelsandshearwaters haveeither:1)Highphenotypicplasticity.2)Highdispersalabilityor3)High evolvability.

Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Skuas

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange: GreatSkua

1-Hottersummersresultinincreasedheatstressinadultsandchicks.Adults morefrequentlyleavenestsunattendedtothermoregulate,whichexacerbates chickheatstress

Oswald,S.A.,etal.“Heatstressinahigh-latitudeseabird:effectsof temperatureandfoodsupplyonbathingandnestattendanceofgreat skuasCatharactaskua.”JournalofAvianBiology39.2(2008):163-169. In hotsummerspreyavailabilityistypicallylower,sonestingadultsneedtoleave thenesttoforageforlongerperiodsoftime.Theyalsobathmoreregularlyto thermoregulate.Thisresultsinlowerfledglingratesaschicksareunattendedfor longerandleftvulnerabletoheatstress.StudywasconductedonFoula, Shetlands.Notethatstudydoesnotinvestigateatrendintemperatureoverits3 studyyears,butpresentsevidencethattemperatureincreasesandprey shortagesarelinkedandaredrivenbyclimatechange

2-Inhottersummers,adultsmorefrequentlyleavenestsunattendedduetoprey shortagesandtothermoregulate,whichresultsinhigherchickmortalitydueto predation

Oswald,S.A.,etal.“Heatstressinahigh-latitudeseabird:effectsof temperatureandfoodsupplyonbathingandnestattendanceofgreat skuasCatharactaskua.”JournalofAvianBiology39.2(2008):163-169. In hotsummerspreyavailabilityistypicallylower,sonestingadultsneedtoleave thenesttoforageforlongerperiodsoftime.Theyalsobathemoreregularlyto thermoregulate.Thisresultsinlowerfledglingratesaschicksareunattendedfor longerandleftvulnerabletopredation.StudywasconductedonFoula, Shetlands.Notethatstudydoesnotinvestigateatrendintemperatureoverits3 studyyears,butpresentsevidencethattemperatureincreasesandprey shortagesarelinkedandaredrivenbyclimatechange.

3-Changesinpreyavailabilityduringthebreedingseasonhaveledtodecreased fledglingsuccess

Oswald,S.A.,etal.“Heatstressinahigh-latitudeseabird:effectsof

temperatureandfoodsupplyonbathingandnestattendanceofgreat skuasCatharactaskua.”JournalofAvianBiology39.2(2008):163-169.

Lowerfoodavailability(particularlysandeels)meansadultsmustforagefor longer,resultinginthesameproblemasforheatstress:chicksareleft unattendedandvulnerable.StudyonFoula,Shetlands.Notethatstudydoesnot investigateatrendintemperatureoverits3studyyears,butpresentsevidence thattemperatureincreasesandpreyshortagesarelinkedandaredrivenby climatechange.

4-Changesinpreyavailabilityhasledtoincreasedpopulationsize Descamps,S.,etal.“ClimatechangeimpactsonwildlifeinaHighArctic archipelago–Svalbard,Norway.”GlobalChangeBiology23.2(2017):490502. GreatskuaswerefirstobservedbreedingonSvalbardin1970,andtheir numbershaveincreasedrapidlyinrecentyears.Thisismostlikelydrivenby rangeshiftsinpreyspeciesandbecauseofgeneralwarmingoftheclimate.

Long-tailedJaeger

1-Southernpopulationsarebecominglesspopulousorgoingextinctincorrelation withrisingtemperatures.Exactmechanismunknown,probablyrelatedtoprey availabilityorheatstress.

Virkkala,R.andRajasärkkä,A."Northwarddensityshiftofbirdspeciesin borealprotectedareasduetoclimatechange."BorealEnvironment Research16(suppl.B)(2011):2–13. Long-tailedskuashavedrastically reducedinrangeanddensityinFinlandduetoclimatechange,densityin20002009was<50%ofwhatitwasincensusescarriedout1981–1999.Seemstobe partofarangeshiftnorth.Exactmechanismunknown,probablyrelatedtoprey availabilityorheatstress.

ArcticJaeger

1-Changesinpreyavailabilityhaveledtodeclinesinkeyseabirdspeciesthat Arcticskuasparasitise,thusleadingtopopulationdeclinesinskuas.

Perkins,A.,etal.“Combinedbottom-upandtop-downpressuresdrive catastrophicpopulationdeclinesofArcticskuasinScotland.”Journalof AnimalEcology87.6(2018):1573-1586. ArcticskuasinScotlandare decliningdrastically,therearemultiplepotentialcausesbehindthis.Onelikely driveristhedeclineofotherseabirdsduetoclimatechange,whichare importantsourcesoffoodforskuas(usuallybystealingtheirprey).Studylooks atmultiplecoloniesacrossShetlandsandOrkneyIslands.

2-IncreasedcompetitionandpredationfromGreatskuas,duetoanincreasing populationsizeandpreyswapping.

Perkins,A.,etal.“Combinedbottom-upandtop-downpressuresdrive catastrophicpopulationdeclinesofArcticskuasinScotland.”Journalof AnimalEcology87.6(2018):1573-1586. Greatskuasareincreasingin numberandhaveswappedtheirdietfrompredominantlyfishtopredominantly preyingonotherbirds.Greaternumbersofgreatskualeadtolowerfledgling survivalrateinarcticskuas.StudylooksatmultiplecoloniesacrossShetlands andOrkneyIslands.

Dawson,N.M.,etal.“InteractionswithGreatSkuasStercorariusskuaasa factorinthelong-termdeclineofanArcticSkuaStercorariusparasiticus population.”Ibis153.1(2011):143-153. Arcticskuarangeiscontracting acrosstheShetlandsasgreatskuapopulationsgrowandexpand.Theoverall declineinArcticskuaseemstobedrivenbythisandlowerdensityofsandeels, andbothpatternsarepartiallydrivenbyclimatechange.

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

ForgreatskuaandArcticjaegerweincludedthefollowingterrestrialvariables: Meantemperatureofthewarmestmonth,precipitationduringbreedingseason, isolationoflandmass,areaoflandmass,distancetosea.

Forlong-tailedjaegerweincludedthefollowingterrestrialvariables:mean temperatureofthewarmestmonth,precipitationduringbreedingseason,distance tosea.

ForgreatskuaandArcticjaegerweincludedthefollowingmarinevariables:sea surfacetemperature(duringthewinter),salinity,maximumchlorophyll concentration,bathymetry(depthandvariance).

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis

givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2.

Underlyingdataweredownloadedfrom:

Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata

Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata.

Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap.

Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS

databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

GreatSkua keypreyspecies:whiting(Merlangiusmerlangus),bluewhiting (Micromesistiuspoutassou),haddock(Melanogrammusaeglefinus)andpout (Trisopterusesmarkii).Somepopulationsrelyheavilyonpredationofotherseabirds (suchasfulmars,kittiwakesandpuffins)andonfisherydiscards.Thesewerenot includedinourpreyassessment.Preyspecieslistwascompiledfrom:

Jones,T.,etal.“BreedingperformanceanddietofGreatSkuas StercorariusskuaandParasiticJaegers(ArcticSkuas)S.parasiticusonthe westcoastofScotland.”BirdStudy55.3(2008):257-266.

Votier,S.C.,etal.“PredationbygreatskuasatalargeShetlandseabird colony.”JournalofAppliedEcology41.6(2004):1117-1128.

Long-tailedJaeger keypreyspecies:collaredlemming(Dichrostonyx groenlandicus),gray-sidedvole(Clethrionomysrufocanus)andNorwaylemming (Lemmuslemmus).Breedingpopulationsrelyheavilyonrodents,includingcollared lemmings,gray-sidedvolesandNorwaylemmings.Whererodentsarenot common,somepopulationsrelyonkleptoparasitism.Thesespecieswerenot includedinourpreyassessment.Preyspecieslistwascompiledfrom:

Dekorte,J.,AndWattel,J.“Foodandbreedingsuccessofthelong-tailed skuaatScoresbySund,NortheastGreenland.”Ardea76.1(1988):27-41.

Andersson,M.“Populationecologyofthelong-tailedskua(Stercorarius longicaudusVieill.).”TheJournalofAnimalEcology(1976):537-559.

ArcticJaeger keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus).Preyspecieslistwascompiledfrom:

Phillips,R.A.,Caldow,R.W.G.,andFurness,R.W."Theinfluenceoffood availabilityonthebreedingeffortandreproductivesuccessofArcticSkuas Stercorariusparasiticus."Ibis138.3(1996):410-419.

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate

DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

Long-tailedJaeger

SkuashavebeenheavilyaffectedbyclimatechangeinGreenland,inparticulardue tolackofpreyandincreasedpredationduetootherspeciesprey-switching Schmidt,N.M.,etal.“Responseofanarcticpredatorguildtocollapsing lemmingcycles.”ProceedingsoftheRoyalSocietyB:BiologicalSciences 279.1746(2012):4417-4422.

Barraquand,F.,etal.“Demographicresponsesofasite-faithfuland territorialpredatortoitsfluctuatingprey:long-tailedskuasandarctic lemmings.”JournalofAnimalEcology83.2(2014):375-387.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,skuaspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetherskuashaveeither1)Specialisedhabitat and/ormicrohabitatrequirement2)Environmentaltolerancesorthresholds(atany lifestage)thatarelikelytobeexceededduetoclimatechange3)Dependenceon environmentaltriggersthatarelikelytobedisruptedbyclimatechange,4) Dependenceoninterspecificinteractionsthatarelikelytobedisruptedbyclimate changeor5)Highrarity.

Formoredetailandafulllistoftraitssee: Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,skuaspossessed.Inbrief, weconsultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetherskuashaveeither:1)Highphenotypic plasticity.2)Highdispersalabilityor3)Highevolvability.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix1:Terns

Sourcesandreferencesforvulnerabilityassessment

1.1Evidenceforexposure(references)

1.1.1Currentimpactsattributedtoclimatechange: ArcticTern

1-Changesinpreyavailabilityduringthebreedingseasonhaveledtopopulation declines(debated).

Lindegren,M.,etal.“Productivityandrecoveryofforagefishunderclimate changeandfishing:NorthSeasandeelasacasestudy.”Fisheries Oceanography27.3(2018):212-221. Severedeclineinsandeels,whichArctic ternsareheavilydependentonintheUK,hasledtopopulationdeclinesacross theShetlands.Thedeclineinsandeelsislikelylinkedtofisheriesratherthan climatechange,butitisbelievedclimatechangemaybehinderingrecoveryof sandeelpopulations.Sandeelabundanceislowerinwarmertemperatures,soit isplausiblethatclimatechangewillhaveanegativeeffectonsandeel availability.

2-Changesinpreyavailabilityduringthebreedingseasonhaveledtopopulation declines.

Vigfusdottir,F."Driversofproductivityinasubarcticseabird:ArcticTerns inIceland."UniversityofEastAnglia(2012).PhDDissertation. Increasing seatemperaturesaroundIcelandhavebeenlinkedtoreducedsandeel recruitment,whichisthelikelycausebehindrecentpopulationdeclines Petersen,A.,etal.“AnnualsurvivalofArcticternsinwesternIceland.” PolarBiology43.11(2020):1843-1849. Updatedevidencesupportingthe abovestudy,ArcticternsinIcelandaredecliningandlikelycauseiscollapseof sandeelpopulationsrelatedtoclimatechange

3-Arcticternsarearrivingfrommigrationandbreedingearlier

Wanless,S.,etal.“Long-termchangesinbreedingphenologyattwo seabirdcoloniesinthewesternNorthSea.”Ibis151.2(2009):274-285. ArcticternsontheFarneIslandsarearrivingandbreedingearlier.Studyuseda 35-yeardataset.Thestudysuggestsclimaticconditionsinwinteringgroundsor duringthespringmigrationmayhavedrivenphenologicalchange.

Møller,A.P.,Flensted-Jensen,E.,andMardal,W."Rapidlyadvancinglaying dateinaseabirdandthechangingadvantageofearlyreproduction."

JournalofAnimalEcology(2006):657-665. ArcticternsinDemarkare

arrivingandbreedingearlier.StrongcorrelationwithchangesinNAOand temperature.

4-JuvenileArcticternshavebeguntodispersefurther,distancehasincreasedin correlationwithwarmerwinters.Mechanismunknown,butlikelymediatedthrough preyavailability

Møller,A.P.,Flensted-Jensen,E.,andMardal,W."Dispersalandclimate change:acasestudyoftheArcticternSternaparadisaea."GlobalChange Biology12.10(2006):2005-2013. Between1933and1997,themeannatal dispersaldistanceofDanishArcticternsincreasedfromaround10kmtoaround 100km.(Nataldispersalisthemovementfrombirthsitetofirstbreedingsite.) ThewinterNAOindexincreasedoverthesameperiod.Thestudysuggeststhe wNAOmayaffectdispersaldecisionthrougheffectsonthemarineecosystem, andthatincreasednataldispersaldistanceshaveafitnesscostbecausethey delaybreedingandthereforereducerecruitmentprobability.

LittleTern

1-Littleternnestsarefrequentlywashedawaybytidalsurges,sucheventsare becomingmorefrequentorextensiveduetorisingsealevels

Johnson,C.,Sullivan,I.,andNewton,S."TernColonyManagementand ProtectionatKilcoole2017."DepartmentofArts,Heritageandthe Gaeltacht:BirdWatchIreland(2017). LittleternnestsintheUKarefrequently washedawaybytidalsurges(personalcorrespondence),whichhasstrongly contributedtosuccessiveyearsofpoorbreedingandsubsequentpopulation declineintheUK.Risingsealevelexacerbatestheseeffectsandreducesthe amountofsafebreedinghabitatavailable.

2-Asseatemperaturehasincreasedovertime,ternproductivityhasdecreased. Mechanismunknown,butlikelymediatedthroughpreyavailability Burthe,S.J.,etal.“Assessingthevulnerabilityofthemarinebird communityinthewesternNorthSeatoclimatechangeandother anthropogenicimpacts.”MarineEcologyProgressSeries507(2014):277295. Ternproductivityislowerwhentheseasurfacetemperatureishigher. Mechanismprobablylinkedtopreyavailability.Localseasurfacetemperature increasedoverthestudyduration.StudyfocussesonseabirdsinForthandTay region.

SandwichTern

1-Sandwichternsarechangingtheirmigrationtimingandarrivingearlierto breedingsites

Wanless,S.,etal.“Long-termchangesinbreedingphenologyattwo

seabirdcoloniesinthewesternNorthSea.”Ibis151.2(2009):274-285. SandwichternsintheFarneIslandsarearrivingearlier,likelyinresponseto changingenvironmentalcuesinwinteringgroundsoronthespringmigration route.However,therewasnosignificantadvancementinlayingdate.Study usedaroughly30-yeardataset.

2-Sandwichternsarechangingtheirmigrationtiming,bothmigrationand breedingeventsareoccurringlater,makingthebreedingseasonshorter Møller,A.P.,etal.“Climatechangeaffectsthedurationofthereproductive seasoninbirds.”Journalofanimalecology79.4(2010):777-784. Breeding seasonisnowsignificantlyshorterinDenmarkthanitwasin1970(byapprox. 36days).Thisisincorrelationwithrisingspringtemperatures,islikelyin responsetochangesinenvironmentalconditions

1.1.2ChangeinEuropeanrangesizebetweenpresentdayand2100: Usingaspeciesdistributionmodel(SDM)wecorrelatedspeciesoccurrenceduring thebreedingseasonwithanumberofterrestrialandmarineenvironmental variables.SpeciesrangedatacamefromtheEuropeanBreedingBirdAtlas(EBBA2) database.Present-dayand2100terrestrialdataweredownloadedfromthe WorldClimdatabase.WeuseddatafromtheMRI-ESM2generalcirculationmodel (GCM),whichisahigh-performingmodeloverEurope.Present-dayand2100 marinedataweredownloadedfromtheBio-Oracledatabasewhichaverages predictionsofmarinevariablesfromseveraldifferentatmospheric-oceanicgeneral circulationmodels(AOGCMS;forfulldetailsseeAssisetal.,2017).Forthemap presentedinthesummaryweusedrepresentativeconcentrationpathway(RCP) 4.5,whichisan“intermediate”emissionsscenario.Alldatawereat5-minute resolution.

ForCaspiantern,roseatetern,Arctictern,littletern,andSandwichternwe includedthefollowingterrestrialvariables:Meantemperatureofthewarmest month,precipitationduringbreedingseason,isolationoflandmass,areaof landmass,distancetosea.

ForCaspiantern,roseatetern,littletern,andSandwichternweincludedthe followingmarinevariables:seasurfacetemperature(duringthewinter),salinity, maximumchlorophyllconcentration,bathymetry(depthandvariance)

Afterrunningourmodelwegeneratedapresent-daymapwhereeverygrid-cellis givenahabitatsuitabilityscorebetween0and1,where1isverysuitablehabitat and0isnotatallsuitable.Wethencomparedthiswithacorrespondingmapbuilt with2100data,andhighlightedcurrentlyinhabitedareaswhere1)suitabilitydrops

sharply(i.e.bymorethan0.1)and2)suitabilitydropsbelowaprobabilitythreshold setbythemodel.Converselywealsohighlightedareaswheresuitabilityrose sharplyandaboveagiventhreshold.Whileadropinhabitatsuitabilityislikelyto resultinpopulationdeclines,itisnotacertainty,anditdoesnotmeanthata populationwillbeextinctin2100orthatapopulationisdoomedtoextinction.With conservationactionandcarefulmanagement,alongwithchangesinhuman behaviour,suchdeclinesmaybemitigatedorinsomecasesprevented.Forafull explanationofthemodelseetheaccompanying‘Methodology’folderinAppendix2.

Underlyingdataweredownloadedfrom:

Keller,V.,etal."EuropeanBreedingBirdAtlas2:Distribution,Abundance andChange."EuropeanBirdCensusCouncil&LynxEdicions,Barcelona (2020). Sourceofrangedata Fick,S.E.,andHijmans,R.J."WorldClim2:new1-kmspatialresolution climatesurfacesforgloballandareas."InternationalJournalofClimatology 37.12(2017):4302-4315. Sourceofpresent-dayand2100terrestrialdata. Assis,J.,etal."Bio-ORACLEv2.0:Extendingmarinedatalayersfor bioclimaticmodelling."GlobalEcologyandBiogeography27.3(2018):277284. Sourceofpresent-dayand2100marinedata

1.1.3Changesinkeypreyspecies:

Wefirstidentifiedthekeypreyspeciesforeachspecies.Thiscanbevariable acrossaspecies’range,butifavailableevidencesuggestedatleastonemajor populationishighlydependentonaparticularpreyspecies,thentypicallythis specieswouldbeincluded.Listsofpreyspecieswerecompiledfrompublished sources,thenverifiedandexpandedfollowingconsultationwithconservation practitioners.Afterwardswecompiledcurrentandprojectedmapsofpreyrangesto assesswherekeypreyspeciesmaybecomelesscommoninthenearfuture.Ifany ofthekeyspeciesarepredictedtovanishordrasticallyreduceinabundanceinthe currentforagingrangeagivenspecies,wemarkedthisonthesummarymap. Weusedseveralsourcestocollaterangeinformation,butforpreferenceweused datafromCOPERNICUSastheyincludeprojectedabundance.Forspecieswhere thiswasnotavailableweusedhabitatsuitabilityinstead.InallcasesweusedRCP 4.5,whichisan“intermediate”emissionsscenario.ForspeciesintheCOPERNICUS databaseweusedthe0.6maximumsustainableyieldparameter,whichassumes internationalco-operationtoworktowardsfish-stocksustainability.Ourassessment isthereforerelativelyconservativeintermsofchangesinpreyspecies.

ArcticTern keypreyspecies:sandeelspecies(Ammodytesmarinus and

Ammodytestobianus),herring(Clupeaharengus)andstickleback(Gasterosteus aculeatus).Thisspeciesalsopreysonsmallinvertebrates(larvalfish,shrimp, idotea,etc.).Thesearepoorlycharacterisedsohavenotbeenincludedintheprey assessment.Preyspecieslistwascompiledfrom:

Hatch,J.J.,etal.“ArcticTern(Sternaparadisaea),version1.0.”InBirdsof theWorld(S.M.Billerman,Editor).CornellLabofOrnithology,Ithaca,NY, USA(2020).

Eglington,S.,andPerrow,M.R."Literaturereviewoftern(Sterna& Sternulaspp.)foragingecology".ECONEcologicalConsultancyLimited (2014).

LittleTern keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),herring(Clupeaharengus),sprat(Sprattussprattus),sandsmelt(Atherinapresbyter),sardines(Sardinapilchardus)andgobyspecies.Prey specieslistwascompiledfrom:

Shealer,D.,etal.“SandwichTern(Thalasseussandvicensis),version1.0.” InBirdsoftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology, Ithaca,NY,USA(2020).

Eglington,S.,andPerrow,M.R."Literaturereviewoftern(Sterna& Sternulaspp.)foragingecology".ECONEcologicalConsultancyLimited (2014).

RoseateTern keypreyspecies:sprat(Sprattussprattus)andsandeelspecies (Ammodytesmarinus and Ammodytestobianus).Preyspecieslistwascompiled from:

Green,E."TerndietintheUKandIreland:areviewofkeypreyspecies andpotentialimpactsofclimatechange."RSPBReport(2017).

Eglington,S.,andPerrow,M.R."Literaturereviewoftern(Sterna& Sternulaspp.)foragingecology".ECONEcologicalConsultancyLimited (2014).

SandwichTern keypreyspecies:sandeelspecies(Ammodytesmarinus and Ammodytestobianus),herring(Clupeaharengus),sprat(Sprattussprattus), anchovy(Engraulisencrasicholus)andsardine(Sardinapilchardus).Preyspecies listwascompiledfrom:

Shealer,D.,etal.“SandwichTern(Thalasseussandvicensis),version1.0.” InBirdsoftheWorld(S.M.Billerman,Editor).CornellLabofOrnithology, Ithaca,NY,USA(2020).

Eglington,S.,andPerrow,M.R."Literaturereviewoftern(Sterna& Sternulaspp.)foragingecology".ECONEcologicalConsultancyLimited (2014).

CaspianTern keypreyspecies:herring(Clupeaharengus).Preyspecieslistwas compiledfrom:

Cuthbert,F.J.andWires,L.R.“CaspianTern(Hydroprognecaspia), version1.0.”InBirdsoftheWorld(S.M.Billerman,Editor).CornellLabof Ornithology,Ithaca,NY,USA(2020).

Preyrangeinformationforallspecieswerecompiledfrom:

Kesner-Reyes,K.,etal."AquaMaps:Predictedrangemapsforaquatic species."InFishBase:R.Froese&D.Pauly(Eds.)(2019).Availableat: https://www.aquamaps.org

Sailley,S.,etal."FishabundanceandcatchdatafortheNorthwest EuropeanShelfandMediterraneanSeafrom2006to2098derivedfrom climateprojections".CopernicusClimateChangeService(C3S)Climate DataStore(CDS)(2021).https://doi.org/10.24381/cds.39c97304.

1.1.4ClimatechangeimpactsoutsideofEurope

CaspianTern

CaspianternsinNorthAmericahavebeennegativelyaffectedbyheatwaves, warmingseas,severestorms,andincreasedfrequencyofflooding,allofwhichare linkedtoclimatechange.

Suzuki,Y.,etal.“ColonyconnectivityandtherapidgrowthofaCaspian Tern(Hydroprognecaspia)colonyonAlaska’sCopperRiverDelta,USA.” Waterbirds42.1(2019):1-7.

1.2Sensitivity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicatehighsensitivityandidentifiedwhich,ifany,ternspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetherternshaveeither1)Specialisedhabitat and/ormicrohabitatrequirement2)Environmentaltolerancesorthresholds(atany lifestage)thatarelikelytobeexceededduetoclimatechange3)Dependenceon environmentaltriggersthatarelikelytobedisruptedbyclimatechange,4)

Dependenceoninterspecificinteractionsthatarelikelytobedisruptedbyclimate

changeor5)Highrarity.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

1.3Adaptivecapacity(references)

WeusedalistofcandidatetraitsbasedonthatinFoden&Young(2016)that indicateadaptivecapacityandidentifiedwhich,ifany,ternspossessed.Inbrief,we consultedpublishedliteratureaswellasexpertknowledgeandonlinedatabases suchasBirdlife(http://datazone.birdlife.org/)andBirdsoftheWorld(https:// birdsoftheworld.org),toassesswhetherternshaveeither:1)Highphenotypic plasticity.2)Highdispersalabilityor3)Highevolvability.

Formoredetailandafulllistoftraitssee:

Foden,W.B.andYoung,B.E.(eds.)."IUCNSSCGuidelinesforAssessing Species’VulnerabilitytoClimateChange.Version1.0."OccasionalPaperof theIUCNSpeciesSurvivalCommissionNo.59(2016).Cambridge,UKand Gland,Switzerland:IUCNSpeciesSurvivalCommission.x+114pp.

Appendix2:Sourcesandreferences forconservationactionassessment

Duetothevolumeofdatainvolved,wehaveplacedoursupportinginformation detailingourfullmethodologyandlistofreferencesintoaseparatedocument.Itis availabletodownloadhere:www.ZSL.org/seabird-guidelines.

Methodology

Ifyouwouldliketoseeourfullmethodology,pleaseseetheaccompanying “Methodology”folder.Thisdocumentcontainsinformationon:

•Howwecompiledourclimatechangeimpactslistforallspecies

•Howwecompiledourconservationactionevidencebase

•Howweassessedeffectivenessofconservationactions

•Howwescoredstrength,transparencyandrelevanceofconservationactions

•Additionalmethodologyonmodellingapproachandgeneratingoutputs

References

Ifyouwouldlikeafullreferencelistofallstudiesinourevidencebase,aswellas therawdatafortheevidencebasepleaseseethe“References”folder.Thisfolder contains:

•Allreferencesrelevanttoclimatechangeimpacts,andeachspecies’ sensitivityandadaptivecapacitytoclimatechange

•Allreferencesusedtoassessspeciesdiet

•Thefullcitationofeachpaperincludedintheconservationactionevidence baseandadditionaldetails.Additionaldetailsincludethefocalspeciesofeach study,thesamplesizeandlocationofeachstudy,whatthemetricofsuccess wasforeachstudy,whethereachstudyhadpublishedandreplicable methodology,whetherweconsideredthateachstudyhadaclearjustificationof theirmethod,whetherweconsideredthateachstudyhadaclearoutcome,the formofeachstudy,andeachstudy’sexperimentaldesign

•LinkstorelevantConservationEvidencewebsitedata(whereapplicable)

VersionHistory

Thisguidancedocumentiscontinuallyupdated,weincludeabriefversionhistory heretoinformreadersonchangesbetweenversions.Thisversionisv1.1.Itis availabletodownloadhere:www.ZSL.org/seabird-guidelines.

Version1: v1.0: Fullinitialrelease. v1.1: Minorfixes.Errorfoundandnowfixedonivorygullvulnerabilitymap. Additionallabelsaddedtophotos.Versionhistorypageadded.