Volunteer magazine 2015

Making a real difference for birds

From the British Trust for Ornithology

Ma 2015 ke y earthe o the Houf M ar s tin! e

They share our homes, yet remain mysterious: We need YOUR help to unlock their secrets Walking in a winter wonderland

Local bird clubs work together

Garden BirdWatch milestone

First results from the Winter Thrushes Survey

A successful small-scale study of Corn Buntings

We celebrate the first 20 years and look to the future

E d i to r i a l

Welcome... ...I’m not the best birdwatcher in the world – I mistake flying Woodpigeons for Sparrowhawks, get confused by Reed Warblers and Sedge Warblers when they first arrive and I’m absolutely hopeless at gulls. Every spring I am consumed by a new determination to improve my bird ID skills – “this year I’ll nail it” I tell myself. To make matters worse, I’ve just found out that I am ranked at number 25 in the BTO staff chart for the number of ‘complete lists’ added to BirdTrack in 2014 – not a great performance! These things bother me a bit because I know I could do much better if I had more time, commitment and determination.

If you feel a bit like me, join me and give it another go this year. Here are some of the tools I’ll be using to help me along: firstly, I’ll be making frequent use of the BTO Bird ID video tutorials – they’re free and cover a wide range of confusion species including Mistle and Song Thrush, Willow Warbler and Chiffchaff and Common and Arctic Tern. I find a quick refresher before or after an encounter really helps me to seal my learning in.

The second thing that helps me is the practice of taking part in surveys or more informal recording schemes like BirdTrack. Forcing myself to work at identifying species in order to record them accurately pushes me that bit further

with my identification skills. It also helps me to notice more about the context of my sightings and my experience is that the surrounding habitat, sounds, behaviour, time of day etc. all add up to paint a more complete picture, which makes identification easier and more memorable. Surveys can also stretch our knowledge by, for example, forcing us to look at a specific species or a specific part of a species’ lifecycle, as the House Martin Survey will do this year. If you struggle with telling House Martin from Sand Martin or Swallow, this year could be a great year to finally crack it (and there’s a video tutorial for that too, by the way!).

BTO is very lucky that not all of its fantastic volunteer birdwatchers are like me but we can all contribute in our own ways to the important evidence needed to conserve our birds and wildlife. Inside you’ll find information about a range of ways in which you can play your part, whatever your experience or skill level. You’ll also find updates on recent surveys, plans for upcoming surveys and news on how survey data are being used.

However you support our work, I hope you enjoy this magazine and that it inspires you to get stuck in for birds!

Thank you,

Ieuan Evans Associate Director Communications – Engagement

did you know?

A grand total of 224 species were recorded by volunteers doing the Breeding Bird Survey in 2013. The average number of species recorded in a square was 31, but the record went to a square in the Lune Valley, Lancashire, where 77 species were recorded!

Three migrant birds which winter in the arid zone of Africa have shown significant increases between 1995 and 2012. UK Breeding Bird Survey trends for Reed Warbler have increased by 21%, Whitethroat by 35% and Redstart by 45%.

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A Buzzard ringed as a nestling in Cumbria in 1985 reached the grand old age of 28 years, 1 month and 11 days before being found freshly dead in 2013, just 12km from where it was ringed. An Avocet ringed in a nest in 1990 was reported alive 22 years, 7 months and 23 days later in 2013.

Over 3,000 volunteers contribute to the Wetland Bird Survey (WeBS) at over 2,600 sites across the UK. WeBS is the principal scheme for monitoring the UK’s wintering waterbird populations, providing an important indicator of their status and the health of wetlands.

In 2014, more than 1,000 volunteers monitored over 45,000 nesting attempts through Nest Box Challenge and the Nest Record Scheme. The Nest Record Scheme is now in its 76th year and in that time over 1.35 million nest records from 232 different species have been sent in.

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c o n t e n ts

In this issue... pg16

pg8

pg20

pg10 Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Join Ieuan in increasing your bird knowledge!

Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Cover photographs: Paul Sterry: NPL/Northeastwildlife.co.uk/Luke Delve Contents: david tipling davidtipling.com/Davidklaer.com/luke delve

Recent survey round-up . . . . . . . . . . . . . . . . . . . . . 4

Woodland soundscape . . . . . . . . . . . . . . . . . . . . . . 10 Learning bird songs and calls can really help your birdwatching in habitats where visibility can be impeded.

Busman’s holiday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Find out how BTO staff are involved in a range of demographic surveying in their own time.

A local perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Butterflies and birds . . . . . . . . . . . . . . . . . . . . . . . . . 20 It’s not all about the birds as BBS surveyors contribute to national butterfly monitoring, and find out about a fabulous joint membership offer.

News on Nightingales, Woodcocks, NEWS and regional network changes.

How a group of bird clubs got together to find out more about the Corn Bunting.

Homing in on House Martins . . . . . . . . . . . . 6 2015 is the year of the House Martin Survey and we need YOUR help!

Understanding our winter visitors . . . 14 The first results of the Winter Thrushes Survey are revealed.

Home-grown science . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Going anywhere this summer? . . . . . . . . . 16 Your holiday bird records will be essential for the next European Breeding Bird Atlas.

Celebrating 20 years of Garden BirdWatch and the amazing science it has unlocked.

A new chapter for herons . . . . . . . . . . . . . . . . . 22 The Heronries Census is about to go online, marking a new phase in our longest running survey, and one that has tracked some surprising changes thoughout its history.

The British Trust For Ornithology

ISSN 0005 – 3392

Contact us BTO, The Nunnery, Thetford, Norfolk, IP24 2PU Telephone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01842 750050 Facsimile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01842 750030 E-mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . btonews@bto.org Website . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . www.bto.org BTO Scotland, Cottrell Building, University of Stirling, FK9 4LA Telephone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01786 466560 Facsimile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01786 466561 E-mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . scotinfo@bto.org BTO Cymru, Thoday Building, Deiniol Road, Bangor, Gwynedd, LL57 2UW Telephone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01248 383285 E-mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . kelvin.jones@bto.org The BTO promotes and encourages the wider understanding, appreciation and conservation of birds. Registered Charity no. 216652 (England & Wales) no. SC039193 (Scotland)

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Patron HRH The Duke of Edinburgh, KG, KT President Chris Packham Chairman Tony Fox Honorary Secretary Frances Hurst Honorary Treasurer John Osmond BTO Volunteer magazine JNCC — All references to JNCC in Volunteer refer to the Joint Nature Conservation Committee, which is the statutory adviser to Government on UK and international nature conservation, on behalf of the Council for Nature Conservation, Natural Resources Wales, Natural England and Scottish Natural Heritage.

Editors Ieuan Evans and Su Gough Layout, design, imagesetting and typesetting O’Connor Design Consultants

Printing Reflex Litho, St Helen’s Way, Thetford, IP24 1HG BTO Membership Individual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .£34 Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . £44 Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . £850 Fellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . £56 Family Fellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . £66 Life Fellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . £1400 Fellows receive Bird Study journal.

When you have finished with this magazine, pass it to a friend or recycle it.

The views expressed by the contributors to this magazine are not necessarily those of the Editor, the Council of the BTO or its committees.

The Editor welcomes any articles on birds. © BTO 2015. Quotations should carry a full acknowledgement.

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R e c e n t s u rv ey ro u n d - u p Survey update

Catching up with Nightingales Rather a lot has happened since the survey was begun back in 2012, say Greg Conway and John Marchant.

Firstly, additional surveying was required in 2013 to provide adequate coverage of regions under-sampled in the first year. Extra effort was concentrated into Suffolk and Essex, where the survey workload had been especially heavy.

Also, in 2013, BTO became heavily involved in providing impartial data on Nightingales in relation to the proposed Paul Sterry: NPL

Lodge Hill development in Kent, which is also the single most important site for Nightingales in Britain. Of critical importance was whether or not the site held more than 1% of the UK grand total of singing male

A preliminary population of only around 6,000 singing male Nightingales was estimated in 2012.

Nightingales since, if it did, the existing SSSI designation could be extended to provide

process but has resulted in a novel and

county population estimates, will be made

statutory protection for the Nightingales.

highly sophisticated modelling approach,

available on the survey page: www.bto.org/

The high-profile political interest and

which will set a new standard for future

nightingale-news

perceived opposing controversial moves

surveys.

Meanwhile, a preliminary estimate of

to upgrade the site designation or pursue

Two papers are in progress for 2015,

approximately 6,000 males in 2012 has

the development meant that the national

the first documenting the new population

been published on the BTO’s BirdTrends

population estimate provided by BTO had to

modelling approach and the other

web pages. This represents a sharp decline

be sufficiently robust to pass Defra scrutiny.

examining changes in abundance and

from the 1999 survey, for which population

Achieving this has been a time-consuming

distribution. Updates and outputs, including

estimates need to be revised upwards.

BTO/GWCT Woodcock survey and annual monitoring The results from 2013 have been analysed and will be published in a paper examining changes in both abundance and distribution since the 2003 survey, including a longerterm assessment of distribution change using Bird Atlas 2007–11 data. A second paper is planned, which will examine changes in habitat use and the potential influence of a

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broader range of factors such as deer, disturbance and soil moisture levels.

See www.bto.org/woodcock-survey for results and updates.

Annual counts have been undertaken at around 25 sites throughout the period between the 2003 and 2013 surveys and these have highlighted the steady reduction

in breeding numbers, which is a cause for concern. In 2014, the counts continued and the number of sites was increased to 150, which will provide greater capacity for monitoring future changes. More monitoring sites are still needed, so please continue to cover your 2013 survey square, or contact Greg Conway (woodcock@bto.org) for details on how to take part.

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R e c e n t s u rv ey ro u n d - u p Non-Estuarine Waterbird Survey

News about NEWS From Lundy to Loch Linnhe and Seahouses to Scrabster, plans for next winter’s Non-Estuarine Waterbird Survey (NEWS) are taking shape!

Changes to our Regional Network Our volunteer Regional Representatives (RRs) do a fantastic job representing BTO at the local level, organising surveys, being the point of contact for local members and volunteers, organising events and so much more. Here we thank the RRs that retired during 2014, and welcome aboard the new ones that have joined us.

Laurie Campbell: NPL

Retiring Regional Representatives Arthur Brown . . . . . . . . . . . . Argyll (N) 2009–2014 Roger Warren . . Buckinghamshire 2010–2014 Mark Eddowes . . . . Cheshire (NE) 2008–2014 Mark Eddowes . . . . . . . Cheshire (S) 2013–2014 Clive Hartley . . . . . . . . . . . . . . Cumbria 2002–2014 Alastair Flannagan . . Glamorgan (W) 2011–2014 James Gloyn . . . . . . . . . . Isle of Wight 1992–2014 Jean Roberts . . . . Lancashire (NW) 2005–2014 Steve Suttill . . . . . . . . . . . . . Manchester 2003–2014 Bob Proctor . . . . . . . . . Moray & Nairn 1994–2014 Richard Paul . . . . . . . . . . . . . . Perthshire 2005–2014 Harry Green . . . . . . . . . Worcestershire 1972–2014

Some waders, such as Turnstone, are not as frequently encountered on sandy/muddy habitat, preferring rocky shores, but results from WeBS and NEWS show that these species are in decline.

NEWS will repeat similar surveys

and passerines such as Rock Pipit,

undertaken in the winters of 2006/07,

and collect information on the tidal

1997/98 and 1984/85. Past results

wrack resource on beaches. Stretches

showed that numbers of Ringed Plover,

of non-estuarine coast will be

Sanderling, Purple Sandpiper, Bar-tailed

allocated to volunteers, and there will

Godwit and Turnstone have fallen on

be opportunities for groups of keen

the Scottish coast, contributing to UK

birders to undertake expeditions to

population declines. Many of these

important areas. We anticipate that

birds occur in internationally important

some professional fieldwork will be

numbers, yet the remote nature of

needed to fill gaps.

rocky shores and other non-estuarine

Previous NEWS surveys were

coast means it is a habitat which is

primarily funded by the UK’s Country

poorly monitored by the Wetland Bird

Agencies (nowadays: SNH, NE, NRW

Survey (WeBS). Periodic coverage by

and DOENI). Funding for this winter’s

NEWS is therefore a key part of the

survey has not yet been secured – so

UK’s waterbird monitoring programme.

we don’t yet have final confirmation

As well as the key waders, NEWS will include counts of inshore seaducks

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that the survey can take place but we

New Regional Representatives Phil Tizzard . . . . . . . . . . . . . . . . . . . . . . Buckinghamshire Hugh Pulsford . . . . . . . . . . . . . . . . . . . . Cheshire (NE, S) Colin Gay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cumbria Claire Young . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dorset Lyndon Jeffery . . . . . . . . . . . . . . . . . . . Glamorgan (W) Jim Baldwin . . . . . . . . . . . . . . . . . . . . . . . . . . . Isle of Wight John Clarke . . . . . . . . . . . . . . . . . . . . . . . . . . . Londonderry Nick Hilton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manchester Melvin Morrison . . . . . . . . . . . . . . . . . . . Moray & Nairn Ken Graham . . . . . . . . . . . . . . . . . . . . . . Yorkshire (L&W) Steve Davies . . . . . . . . . . . . . . . . . . . . . . . . Worcestershire You can find out more about the Regional Network online (www.bto.org/volunteersurveys/regional-network) and make contact with your local RR. Vacant BTO Regions We have a number of BTO regions with no RR. If you are interested in taking on the role of RR, or part of the job, please contact Dawn Balmer at BTO HQ (dawn.balmer@bto.org or call her on 01842 750050).

Scotland: Angus, Argyll (N), Dumfries (from July), Perthshire, Sutherland England: Essex (NE), Essex (S), Lancashire (NW), Yorkshire (SE), Yorkshire (SW) Wales: Anglesey

will update you as soon as we can.

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H o u s e M a rt i n S u rv ey

Homing in on

House Martins Planning for BTO surveys starts well before fieldwork can take place, to ensure the survey methods are clear and interesting for our volunteers, yet also scientifically rigorous. More pragmatically, we need to ensure that we can fund any survey. Thanks to the generous donations you made in response to last autumn’s House Martin Appeal, we can go ahead with the UK House Martin Survey this year. Survey organiser Ian Woodward brings us up to speed.

on the counts at these sites. In order to use the counts to produce a population estimate, it is essential that squares are picked randomly so that they are representative of the UK as a whole.

This approach is followed for many BTO surveys, including the BBS. so many of you will already be familiar with this concept.

We have been keen to run this

will be to obtain a robust population

survey for several years, particularly

estimate. There are two broad approaches

Habitat basis

after seeing the rapid and dramatic

to choose from: a census or a sample.

For single-species surveys, we

changes in House Martin populations

A census aims to carry out a full count

sometimes use a ‘stratified sample’,

and distributions documented by Bird

by visiting all sites where a species is

grouping squares into different

Atlas 2007–11. Our planning kicked off

known to occur or potentially occurs.

categories (often based on habitat), and

in earnest last summer, when we ran

This is possible for scarcer species which

select a proportion of squares from each

a small-scale pilot survey. Pilot work

are restricted by habitat requirements

category to ensure we cover all suitable

allows us to test our methods and make

to a small number of sites. However,

habitats. House Martins are most likely

decisions about what data to collect

for species with a large and scattered

to breed in small villages or close to the

and how to collect them. Our pilot

population like the House Martin, this

edge of towns, but they can also be

survey enabled us to confirm that the

approach is not possible.

found at sites ranging from dense urban

Instead, a sampling approach is

centres to isolated farmhouses, as well

adjustments to the survey methods. We

needed. A small proportion of sites

as coastal and inland cliffs. Our survey

have also been thinking carefully about

(usually squares) are surveyed and a

will therefore need to cover a wide range

exactly how we will use the data, and

population estimate is calculated, based

of habitats including some of these

survey was feasible and to make some

extremes.

how we can make use of information collected from other sources such as land-use data and satellite images.

Choosing the squares Another important component of survey planning is deciding which sites to cover. The main aim of the 2015 survey

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“Our pilot survey enabled us to confirm that the survey was feasible and to make some adjustments to the survey methods.”

This variability presents us (and our volunteers!) with a challenge – some 1-km survey squares will contain only a couple of houses and will take just a few minutes to survey, others will be entirely urban and may take several hours to cover thoroughly.

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H o u s e M a rt i n S u rv ey

The House Martin Survey has been timed to coincide with the incubation and provisioning of the first brood. Once these have fledged, recordind can get very complicated, with juveniles returning to the nest to help with later broods.

we need your help!

achieve good coverage. You can choose

see if you can cover a square near to your

A robust population estimate from

a square by visiting our website (www.

holiday site. A single visit in June will be

random sample surveys can only be

bto.org/house-martins). If it will take only

better than no visits at all.

made if good coverage is achieved and

a few minutes to cover all of the suitable

no bias is introduced because volunteers

habitat available in your square, please

contain House Martins, occupancy is

select what they perceive to be the better-

have a look to see if you can take on a

unpredictable even in the higher-quality

quality squares. As always, we are relying

second square.

habitat, so we know there will be some

Paul Sterry: NPL

on our excellent network of volunteers to

“Whilst we expect many squares will contain House Martins, occupancy is unpredictable even in the higher quality habitat.�

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Bias can also be introduced because

Whilst we expect many squares will

squares without any House Martins. We

there are fewer people in some parts

know how frustrating it can be to travel to

of the UK, making it harder to achieve

carry out a survey and not find the target

full coverage in these areas. We can

species. However, even if your square has

sometimes control for this sort of bias

no House Martins, these zero counts are

during our analysis, but it is better to

extremely important to produce an accurate

resolve it up-front by surveying more

population estimate, so by submitting your

squares in all regions. If you are going on

zero count you will be making a valuable

holiday in the UK in June, please check to

contribution to the survey.

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G a r d e n B i r dWatc h

Celebrating twenty years of

science in your

gardens There have been big changes at our winter feeding stations over the last 20 years, with new species, such as Blackcap, becoming familiar sights.

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G a r d e n B i r dWatc h

Gardens are often the place where people first encounter birds and other wildlife and learn to love them, says Clare Simm. In addition, gardens are an important habitat supporting a wide range of species. Back in 1995, when Garden BirdWatch (GBW) started, gardens were less appreciated, meaning that funding for garden surveys was hard to come by; so, it is thanks to our supporters that we have made it to our 20th anniversary.

There were predecessors to GBW. The

Thanks to the enthusiasm of Garden

Garden Bird Feeding Survey started in 1970,

BirdWatchers, we have also been able

but due to the lack of external funding, the

to run one-off surveys to answer other

numbers of participants had to be limited.

scientific questions. The Shortest Day Survey

The BTO then managed to secure short-

was run in December 2004 to investigate

term funding for other garden surveys (BTO/

whether there is a pattern to the time at

BASF Garden Bird Survey and BTO/IWC

which different bird species arrive at garden

Garden Bird Enquiry). Eventually, with core

feeders on a winter’s morning. 5,460

funding from CJ WildBird Foods Ltd and

people participated, including a sizeable

the generosity of BTO supporters, Garden

number of Garden BirdWatchers, and it was

BirdWatch was launched and, by the end

discovered that the time at which garden

of 1995, an astonishing 5,028 people had signed up; 708 of those are still contributing

One change over the 20 years is the nowfrequent visits of Long-tailed Tits to feeders.

records to this day.

David Kjaer.com/Northeastwildlife.co.uk/davidtipling.com

For many who joined in 1995, recording

birds begin to forage on winter mornings may be limited by their visual capacity at low light intensities. It was also found that

Sadly, Garden BirdWatchers have also

birds appeared at garden feeding stations

birds for GBW seemed like a natural

charted the decline of some of our well-

later in the morning in urban areas than

progression as they were already noting

known garden bird species. While some,

in rural areas during the winter. This latter

down their garden birds. One Garden

like House Sparrow and Starling, have been

finding prompted us to run the Early Bird

BirdWatcher from Gwent told us that “as soon

declining since before the survey started,

Survey in January 2014, to investigate

as I read about GBW, I realised that it was

others, including Greenfinch, have had

whether light pollution has any effect on

exactly what I’d been waiting for – a chance

their population crashes tracked by GBW.

the foraging behaviour of garden birds. The

for my birdwatching to be of use.” Since

For Greenfinch, BTO scientists were able

results from the latter survey have just been

then he has submitted the most records

to pinpoint when the population started

submitted to a peer-reviewed scientific

from a single site, with his highlight being a

to decrease by combining GBW data with

journal for publication.

Hawfinch – the first he’d ever seen, despite

information from the Garden Bird Health

looking for it in a number of woods!

initiative. This study revealed that the disease

simple things

trichomonosis, originally known from pigeon

In the 20 years of GBW we have had

fascinating findings

species, started to affect Greenfinches

a phenomenal 481 different species

Thanks to 94.7 million species observations

in 2005 and they have been declining

recorded. One garden in Cumbria has

(from 7.3 million weekly submissions), GBW

in gardens ever since, reflecting what is

recorded 167 species, including Water

data have been used to show a variety of

happening in the wider countryside.

Shrew and Grasshopper Warbler. While

fascinating things. These include determining

seeing unexpected species is a buzz for any

seasonal patterns, such as the autumnal dip in

Garden BirdWatcher, many of them told us

Blackbird reports, how the weather can affect

that it is the simple things that keep them

garden use, such as the phenomenal rise in

hooked. One, from Gloucestershire, said “It

reports of Blackcap during the cold weather

[GBW] provides an opportunity to watch bird

in March 2013, and how garden use has

behaviour – the reaction when a Sparrowhawk

changed over the last 20 years. Goldfinches

is about, the ‘pecking’ order between species,

were reported from an average of only 12% of

the arrival of Blackcaps in winter compared

GBW gardens in 1995 but, by 2012, an average

with timings in previous years…”

of 63% of gardens had reported them. This

It is the long-term records of common

increase in garden use has been attributed

species that have allowed us to find out as

to changes in the food that we provide for

much as we have, so a huge thank you to

birds, with nyger seed and sunflower hearts becoming more common food items and much to the Goldfinches’ liking.

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Want to know more about GBW and the birds that use your garden? Visit www.bto.org/gbw.

those who currently take part in GBW and those who have taken part in the past – your time and devotion are much appreciated.

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B i r d I d e n t i f i c at i o n

A walk in the woods: a springtime soundscape One of the greatest birding joys is a walk through spring woodland, soaking up the sights and sounds as our birds enter the breeding season. Birdwatching in woodland can be frustrating, however, as the birds often remain resolutely hidden behind the new spring leaves. Being familiar with their songs and calls will equip you with a whole new way of both finding and recognising birds, and might help you home in on a target species. Come with Ben Darvill and Su Gough on a walk through the woods to see this in action…

As we set off through the fresh green

or ‘primary projection’, however, the simple

tits suggests otherwise and our curiosity is

morning, we are surrounded by mature

repetitive ‘chiff-chaff’ song immediately gives

rewarded with splendid views of a Lesser

broad-leaved woodland, with the sun filtering

its identity away!

Spotted Woodpecker; their raptor-like call is a

down through the new leaves. Away from

Another frequent song is the bell-like

good one to learn! We make a mental note

the path the ground is almost devoid of

ringing ‘teacher-teacher’ of Great Tit, but a

to look more closely at the foraging mixed tit

plants, but there is vegetation from shoulder

sudden sneezed ‘pit-chou’ alerts us to the

flocks which roam through these woodlands

height and upwards to the tops of the

presence of a Marsh Tit. This is the call, and

in winter – these diminutive woodpeckers

trees. Common birds are all around and will

we probably won’t hear Marsh Tits singing

have a habit of joining them.

accompany us on the whole of our walk:

today as, for them, the breeding season is

the short, sweet, melancholy phrases of

already well advanced. As we move past one

area with large conifers. The feel of the wood

Robin; the melodic, thin, metallic song of

large tree a loud ‘kek, kek’ echoes around

changes completely, as do the sounds we

the Dunnock and the fluty, rich and luscious

and we stop and wait until the Great Spotted

are hearing. The most frequent are short,

Blackbird song. Almost at once we spot a

Woodpecker moves around the trunk and

soft contact calls, but we are not confident

small warbler high in the tree tops. From this

reveals itself – a stunning male with his red

to identify these until one of the birds starts

distance and angle there is no way

nape patch. Then we realise that he has his

singing, a jaunty hop-skip ‘dee-d-lee-dee-d-

nest hole high on the same tree – the young

lee’ with a finishing flourish – confirming the

we could look at the leg colour the Visit rsion of e ve hear onlin rticle to ds n a this bird sou ! the scribed de

We carry on walking, entering into an

are calling from within. We move on, to allow the adult to feed his chicks in peace. dramatic action A thin, high ‘shree-shree-shree’ call emanates Northeastwildlife.co.uk/david tipling davidtipling.com/Andy Mason

from another trunk and we turn to scan the tree with binoculars, finally spotting the small mouse-like Treecreeper heading up the trunk.

We would have missed it completely if we hadn’t heard it first! Suddenly there is a burst of very high-pitched simple ‘seeet’ whistles from the birds around us and, recognising this as the ‘avian predator alarm call’ of many small birds, we look around for the cause. We’re rewarded with the sight of a silent female Sparrowhawk flashing fast and low through the trees.

Panic over, the birds return to more relaxed behaviour. Suddenly, a loud ‘kee-kee-keekee-kee-kee-kee-kee-kee-kee-kee’ call echoes Stock Dove is often over looked as a Woodpigeon, unless its distinctive song is known.

10

out, and we wonder if the Sparrowhawk has returned but the relaxed behaviour of the

Birdwatching in woodland can be frustrating, but easier if you let the songs and calls help you.

BTO Volunteer Magazine | 2 015

B i r d I d e n t i f i c at i o n

How to tune in…

If you’ve been inspired to improve your knowledge of bird songs and calls, here are some top tips.

Access the online version of this article and listen to the songs and calls that we’ve featured. Visit www.bto.org/woodland-song.

Invest in an audio-guide which is optimised for learning. Geoff Sample’s Bird Songs and Calls is recommended. The 3-CD set takes you through different habitats, allowing you time to try identifying each species before the narration gives you the right answer.

Test yourself. Why not stop for a minute when you’re out on a walk and actively listen. You could even shut your eyes. Try and identify everything that you can hear, then use your binoculars to search out those species that you were uncertain about.

Learning songs and calls can help your birding in numerous ways, including enabling you to go into an area armed with another way of locating and identifying a target species, such as the scarce and elusive as Lesser Spotted Woodpecker.

birds as Goldcrests. We hear ‘teacher-teacher’ again, but this time the song lacks the strength and bell-like ringing quality heard earlier, instead sounding weaker, reedy and slurred, identifying the bird as a Coal Tit this time, the difference in quality of song being the clincher. helping to target We move out into a more open shrubby area,

Make up your own mnemonics - you’re more likely to remember yours than other people’s. For example, Ben remembers Chaffinch song as ‘ha ha ha ha, ha ha ha ha, ha ha ha! I shot you!’ It works for him!

“There is a different warbler singing from the shrubs in our wood – a beautiful, complex, rich and fluty song. The big question – is it a Blackcap or Garden Warbler?”

The bird does not reveal itself, however, so there’s still a little doubt in our minds.

A maniacal laughing call is much easier to identify: a Green Woodpecker ‘yaffling’ and, as we walk around the corner into a grassy clearing, we interrupt its Wood Ant meal and it bounds away up into the trees. We are back in broad-leaved woodland now, and a large bird passes overhead, silhouetted against the sky.

As we walk into the more open area

It calls, a cat-like mewing: a Buzzard. Just as

edge of the conifer patch and it’s in this area

there are piles of brash lying around and a

we leave the wood, a low distinctive ‘whoo-

that we hope to catch up with one of our

machine-gun-like song resounds from low

whoo-whoo’ draws our attention to a pair of

target species. A few moments scanning the

down in these piles. It’s a Wren – one of

Stock Dove perched in one of the larger trees

trees for movement produces nothing. Then

the loudest birds for the size of its body.

– we could easily have missed them amongst

we hear another Goldcrest singing. But wait!

There is a different warbler singing from the

all of the Woodpigeons, if their song wasn’t so

Is it a Goldcrest? The song is similar (it’s clear

shrubs in our wood – a beautiful, complex,

distinctive.

and high-pitched), but it lacks the jaunty hop-

rich and fluty song. The big question – is

skip notes, sounding more like an accelerating

it a Blackcap or Garden Warbler? A difficult

our ability to identify at least some of the

‘dee-dee-dee-dee-dee-dee’ with a less

one this, but the bird in front of us is singing

species we heard by sound. You never stop

flamboyant finish. Finally we see movement

with a steady pace and the ‘verses’ seem

learning, however, and this is one of the joys

low down and watch through binoculars as a

well-practised and not over-long. Each phrase

of discovering bird songs and calls, there are

beautiful male Firecrest emerges briefly but,

seems to start tentatively but finish in a rich

always new species, new sounds and even

thankfully, for long enough to see the face

and confident manner. We are pretty certain,

familiar species making a sound you have

stripes and chestnut shoulder patch. Excellent!

therefore, that we are listening to a Blackcap.

not encountered before.

but there is a stand of Douglas Firs on the

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A great walk, which was enhanced by

11

F o c u s o n Vo lu n t e e r s

focusing in on the details

Corn Buntings: a local perspective

Recent years of atlas fieldwork uncovered many birdwatchers who had not previously participated in surveys and were keen to contribute to our understanding of changing bird populations. Chris Dee, BTO Regional Representative for Hertfordshire, describes how three neighbouring bird clubs collaborated to harness this untapped potential for a Corn Bunting Survey in 2014.

12

The Herts Bird Club has a long history of

in the distribution of Corn Buntings of

monitoring breeding Corn Buntings and so

between 27% and 62% over the past

welcomed the opportunity to work together

20 years – but these projects were not

with the Bedfordshire and Cambridgeshire

designed to measure population size in the

Bird Clubs to design and run a survey of

way that a targeted survey could. The atlas

the species. With plenty of enthusiastic local

fieldwork however did provide useful clues

volunteers, this was a good opportunity

about where to focus our volunteer effort.

to provide interest for local birdwatchers

By randomly selecting a fifth of the tetrads

and contribute some useful information

(2-km x 2-km squares) where birds had

about this enigmatic species in one of its

been located in recent breeding seasons,

strongholds in eastern England.

surveyors could have a reasonable degree

Results from recent tetrad-scale atlases

of confidence that they would find the target

in the three counties identified reductions

species. Data from the previous atlas period

BTO Volunteer Magazine | 2 015

Luke delve

Corn Buntings are declining in range but in favoured locations can still be found at high densities. Joining in a local bird club survey can help us to understand more at a fine scale.

F o c u s o n Vo lu n t e e r s

“There was a very positive response from local birdwatchers; 91% of the priority tetrads were surveyed and a further 66 extra squares were also visited.”

Working together locally

(1988–92) were also used to provide a smaller sample of tetrads (10%) from which birds had recently disappeared. The aim was to cover 146 tetrads across the three counties whilst giving the more enthusiastic volunteers the flexibility to take on extra squares.

We built a website to show the survey squares and provide printable survey forms and the survey was publicised through the bird clubs’ websites and at meetings.

Advice on survey timing was sought from Rosemary Setchfield who has been working on Corn Buntings in north Hertfordshire with the RSPB. We asked volunteers to visit their chosen locations on two occasions; once in the first three weeks of June and once in the first three weeks of July, plotting the position of all Corn Buntings on the maps provided.

There was a very positive response from local birdwatchers; 91% of the priority tetrads were surveyed and a further 66 extra squares were also visited. Analysis is currently under way, with the hope that the results can help to identify population hotspots that could be targeted for agri-

The Three Counties Breeding Corn Bunting Survey is an excellent example of local bird clubs working together to discover more about a species with the aim of establishing the population size, which may well lead to local conservation action.

Although the BTO is able to organise periodic UK single-species surveys in addition to our core monitoring schemes, there is still much that can be learnt through local co-ordinated fieldwork. The most recent published assessment of population estimates of birds in the UK highlighted many opportunities for volunteers to make a significant contribution to our knowledge.

The report identified a suite of species for which better local population density estimates would greatly aid the difficult task of estimating population size. Examples of species suitable for small-scale local studies

include: Breeding ducks such as Mandarin, Gadwall, Teal, Eider, Red-breasted Merganser, Goosander.

Breeding waders, especially in the uplands.

Breeding owls and birds of prey such as Little Owl, Tawny Owl, Hobby, Kestrel.

Breeding Water Rail, Rock Pipit, Kingfisher, Sand Martin, Black Redstart, Willow Tit, Lesser Spotted Woodpecker.

Widespread wintering species such as Yellowhammer, Water Pipit.

Wintering waterbirds in the wider countryside such as Mallard, Moorhen.

If you’re interested in co-ordinating a local small-scale study and would like some advice on methodology, BTO would be keen to support you. Please contact Dawn Balmer (dawn.balmer@bto.org).

environment advice.

Tips for running a local survey…

Identify a species that local atlas work has shown to be in decline or a county BAP species, but not one that is so scarce that volunteers are unlikely to find it.

Investigate collaborations with other local bird groups.

Decide on survey methods and sampling strategy, consulting with experts or published literature. Decide what will be counted, when and in what size survey areas.

2 015 | BTO Volunteer Magazine

Select areas to be surveyed; random sample, stratified random sample based on prior distribution knowledge or habitat features, or a complete survey of the entire area. Tailor this based on an estimate of how many birdwatchers may participate.

Determine a way to allocate survey plots to observers to avoid duplication of effort, through local organisers or a

website or web page.

Publicise the survey through local bird club websites, meetings, newsletters and social media.

Distribute instructions and survey forms in good time.

Provide feedback at the end of the fieldwork season.

Write up the results for local bird report or even a national journal.

13

W i n t e r T h ru s h e s S u rv ey

Winter Visitors

Fieldfare

Thousands of thrushes migrate to the UK from mainland Europe to take advantage of our relatively mild winter conditions. But precisely how many come, how they are distributed around the UK, and what they feed on whilst they are here is not well known. The Winter Thrushes Survey was designed with these questions in mind and ecologist Kathryn Ross has been delving into the data.

The survey ran over two winters

The survey data are being used to

number of thrushes present in the UK at

(2012/13 and 2013/14), and data were

investigate two key questions, both still in

collected by 1,957 BTO volunteers from

progress:

this time of year.

Investigating between-species and

Determining a population estimate

more than 4,000 unique 1-km squares

geographical differences in the use of

within the UK. Many surveyors visited their

for winter thrushes in the UK, using count

foraging habitat and food preferences

squares multiple times throughout winter,

data from ‘core squares’ that were surveyed

throughout the two winters, to help identify

providing vital information on how the

between December 27 and January 10. The

key resources and potential factors in the

habitat usage and food preference varied

abundance data collected during this core

patterns of change observed in numbers of

through the winter months.

period will give us an estimate of the total

breeding and wintering thrushes.

Fig 1 Foraging habitat preferences for the five winter thrush species Blackbird Blackbird

Foraging habitat preference in each month Fieldfare Fieldfare

Mistle MistleThrush Thrush

Redwing Redwing

Habitat Key

Song Thrush Song Thrush

Habitat

OCT Oct NOV Nov DEC Dec JAN Jan FEB Feb MAR Mar APR Apr

Woodland Woodland 0.75

1.00 1.00

0.50

0.75

0.25

0.50

0.00

0.25

0.75

0.00 1.00 1.00

0.50

0.75

0.50

0.00

0.25 0.25

0.75

0.00 1.00 1.00

0.50

0.75

0.50

0.00

0.25 0.25

0.75

0.00 1.00 1.00

0.50

0.75

0.50

0.00

0.25 0.25

0.75

0.00 1.00 1.00

0.50

0.75

0.50

0.00

0.25 0.25

0.00 14

Proportion of observations Proportion of observations

Data from the 2012/13 and 2013/14 winters were combined to show the proportion of foraging observations occurring in each habitat each month.

BTO Volunteer Magazine | 2 015

Northeastwildlife.co.uk

Amenity land Amenity land Brownfield/ Brownfield/industr industrial Coastal habitats habitats Coastal Cropped Cropped farmland farmland Moorland/heath Moorland/heath Open parkland Open parkland Orchard Orchard Pastoral land Pastoral land PrivatePrivate gardens gardens

SEP Sep

W i n t e r T h ru s h e s S u rv ey

Mistle Thrush

Where do thrushes feed?

So far, we have found that the habitats

Conservation of thrushes

used for foraging vary between species and throughout the winter (Fig 1). For Redwing and Fieldfare, pastoral land increases in importance as the winter progresses. Fieldfare were more reliant on pastoral land and cropped farmland than other species, and this habitat specificity was even more pronounced in the spring months. In contrast, for Song Thrush, Mistle Thrush and Blackbird (which are back on territories and starting to breed by March in the UK), use of pastoral land appears to lessen in April. Blackbird showed less variation in habitat preference throughout the survey period compared with the other species, with private gardens, woodland and amenity land remaining important throughout the winter period. The geographical variation in these habitat preferences is still being investigated.

Acknowledgements The Winter Thrushes Survey was funded by members and volunteers through the BTO Raffles in 2011/12 and 2012/13Â and generous donations from charitable trusts: The Benham Charitable Settlement/The Mitchell Trust/Keith Ewart Charitable Trust/The Saxham Trust/The Harris Charitable Trust/Marjorie Coote Animal Charity Trust

2 015 | BTO Volunteer Magazine

Breeding populations of thrushes in the UK are significantly lower than they were in the 1970s, although the trajectory of change has varied between species.

Blackbird and Song Thrush numbers declined steeply throughout the 1970s and 1980s, levelled off in the mid-1990s with a period of increase between 1995 and 2005; but a downward trend has again been observed in more recent years.

Mistle Thrush, on the other hand, has declined steadily since the 1970s, with no indication of levelling off. The reasons for these declines are not well understood but reduced survival of first-year birds and shifting of populations due to climate change may play a role.

While Fieldfare and Redwing are ‘red listed’ in the UK according to the Birds of Conservation Concern criteria, this is on the basis of changes in our very small breeding populations of these species, so it tells us nothing about the much larger

European populations that breed on the Continent and visit the UK in the winter.

According to the Pan-European Common Bird Monitoring Scheme (PECBMS) data, Redwing populations throughout Europe are relatively stable, but Fieldfare has suffered a moderate decline in the last two decades.

Song Thrush is on the UK red list due to its declining breeding populations, while Mistle Thrush is currently amber listed and continuing to decline. For these species, where there is considerable overlap between the UK breeding and wintering populations, changes in winter survival are likely to impact the breeding population numbers. The more informed we are about foraging habitat, food preferences, and the availability of these resources throughout the winter, the more we can do to ensure that the right sort of habitat and resources are available at the right time of year to sustain our winter thrushes.

15

B i r d r e c o r d i n g i n E u ro pe

The new European Breeding Bird Atlas The European Bird Census Council (EBCC) has embarked on an ambitious new project to produce the second European Breeding Bird Atlas (EBBA2), reports David Noble. The original ground-breaking book, organised by the EBCC and edited by Ward Hagemeijer and Mike Blair was published in 1997 and collated information from birdwatchers in order to map the distributions of all of Europe’s breeding birds.

Submit any non-standardised bird records (akin to roving records) which must include the date, geographical location, name and contact details of the observer and any evidence of breeding. Lists of all species seen in a 50 x50-km grid, or smaller area, are also extremely valuable.

Do a standardised or timed survey.

This first atlas has proved a powerful

available online in a valuable resource for

Methods for these vary between countries

tool for conservation, for identifying

future research and conservation action.

and observers are recommended to contact

hotspots, addressing the impact of

As you can imagine, there are huge

national co-ordinators in priority countries

changes in climate and land-use and for

logistical challenges, particularly in

(available on the EBCC website www.ebcc.

assessing the effectiveness of conservation

achieving coverage where there are very

info/index.php?ID=545). Where this is not

action. New data are now needed to

few birdwatchers. One of the most valuable

possible, the best option is a complete species

address emerging conservation issues, and

legacies of the first atlas was increased

list from a timed (1–2 hour) visit to a specified

birds have proved themselves very useful

co-operation across the European

geographical unit, such as 1 x 1-km, 2 x 2-km,

proxies for biodiversity more broadly.

ornithological community. This has

or a route.

EBBA2 will:

strengthened since, with new conservation and birdwatching organisations in countries

One of the easiest ways to contribute

distribution maps for all breeding species

in the east and south of the continent

records is to use BirdTrack. This free system

in Europe.

and the development of common bird

now allows users to submit data from

monitoring programmes in countries from

anywhere in the world. All breeding bird

Poland to Bulgaria.

data submitted via BirdTrack will be made

Provide better, more accurate up-to-date

Show patterns of relative abundance at a European level for the first time.

available to EBBA2 and national atlases, as

Show changes in species distributions since the last atlas.

What can you do to help?

will data from most of Europe’s other online

Build capacity for conservation and

All UK bird records (particularly those with

bird-recording systems. Otherwise, roving

monitoring in areas of Europe where this

breeding evidence) collected by schemes

records or species lists from timed visits can

is most needed.

such as BirdTrack, NRS, the Ringing Scheme,

simply be sent in a spreadsheet to national

BBS, periodic surveys and the Rare Breeding

co-ordinators or directly to the EBCC.

The project is led by the EBCC and its

Birds Panel will be used and extremely

partner organisations and the geographical

valuable.

Here’s your chance to get an atlasing fix, explore exciting parts of the continent, see

scope encompasses all of Europe including

However, you can also help if you

great birds and help a vital project at the same

Turkey and European Russia. The extended

are outside of Britain and Ireland. Every

time. Advice for travelling birders is available at

geographical scope brings exciting new

spring and summer thousands of UK

the EBCC website and 19 countries in eastern

species such as Brown Fish Owl and

birdwatchers spread out across Europe

and south-eastern Europe have appealed

Grey-necked Bunting to a list that currently

in search of sun, new experiences and

for particular help. National co-ordinators for

extends to 582 native and 63 non-native

exciting birds. Whether grabbing an hour

these countries would be delighted to hear

species. The focal period for data collection

or two around a Mediterranean salt-pan or

from observers, from groups and from tour

is 2013–17 and, at a minimum, data will be

exploring high Caucasian peaks in search

operators who are interested in contributing.

needed for each 50-km x50-km square for

of Great Rosefinches, all birders abroad

We have already seen special expeditions

comparison with the last atlas. The new atlas

can help.

by German birders to Albania, Czechs to

will ultimately be presented in a book and will embrace the new digital world, making interactive maps and additional material

16

As with Bird Atlas 2007–11, there are two main ways to contribute:

Macedonia and Moldova, and Catalonians to Montenegro and Turkey: what can the Brits contribute?

BTO Volunteer Magazine | 2 015

B i r d r e c o r d i n g i n E u ro pe White-throated Robin

Slender-billed Gull

Kentish Plover

Purple Gallinule

Black Wheatear

Cretzschmar’s Bunting

fan-tailed warbler

Ortolan

luke delve/davidkjaer.com

Sardinian Warbler

Birding in Europe is hugely popular, with a wide range of species present. If you visit anywhere in Europe over the next few years your records will be valuable for the second European Breeding Bird Atlas. Put your records into BirdTrack and remember breeding evidence.

2 015 | BTO Volunteer Magazine

17

L i f e c yc l e

Demography

on the doorstep

There may be snow on the ground as Ruth Walker and Dave Leech write, but many species are already gearing up for the breeding season. Dunnocks and Song Thrushes have been in good voice for some weeks, with Great Tits a recent recruit to the chorus. And as the birds start to stir, so too do BTO volunteers…

…including many staff members, for the allure of the field is greatly exacerbated by the day job; there’s no better incentive to get out and collect data than amazing volunteers telling you about their fantastic projects all day. Of the 113 current BTO employees, 44% are either qualified or trainee ringers, so the capacity for demographic monitoring of populations is considerable and the birds of Breckland provide an excellent weekend focus.

The original aim of the Ringing Scheme was to explore movements of birds and, while advances in tagging have greatly increased our knowledge of migration routes and destinations, the fitting of metal rings still constitutes a valuable tool for studying dispersal. However, the principal use of ringing data in the 21st century is to estimate survival rates which, in conjunction with productivity (NRS www.bto.org/nrs), help to identify the causes of population increases and declines.

The less things change Interpreting ringing data is much more straightforward if the effort invested doesn’t vary over time, as surviving birds have the same chance of being detected from one year to the next. Changes in the numbers handled also become meaningful indicators of abundance and breeding success rather than simply reflecting hours in the field. This is the ethos behind the Constant Effort Site (CES www.bto.org/ces) scheme, where the same mist nets are erected in the same places at the same times each year.

18

Justin Walker/steven round stevenround-birdphotography.com/Niall Burton

data provided by the Nest Record Scheme

1 BTO Volunteer Magazine | 2 015

L i f e c yc l e

The Breckland region is littered with

in Thetford, focusing on Blackbirds

staff-operated CES, the longest-running being

and Woodpigeons/Collared Doves

Peter Lack’s site at Lackford Lakes, initiated in

respectively. Incredibly, Allison’s project

1995. Stephen Baillie’s site at Redgrave and

has demonstrated that over 100 breeding

Lopham Fen followed in 1997, with the BTO

adults visit their small suburban garden in

Nunnery reserve two years later. Hinderclay

a single breeding season. Lee also leads

Fen and Cranwich gravel pits were both added

on a study of Greylag and Canada Geese

to the list in the last decade. Given these are

in the town, the birds having been fitted

predominantly wet scrub and reedbed sites, it’s

with neck collars, clearly visible even

no surprise that a lot of Reed Warbler data are

when they are on the water; while many

collected, but good numbers of other migrant

hang around on site throughout the year,

(Chiffchaff, Blackcap, Garden Warbler) and

others prefer to wander, a few moving as

resident songbirds (Blue Tit, Wren, Dunnock)

far as the North Norfolk coast.

are also encountered.

2 1. Reed Warbler is the most commonly encountered species across Breckland CES sites. At Cranwich, birds are also fitted with colour-rings to allow identification at the nest.

2. Ringing of Siskins in Thetford Forest throughout the year is providing valuable data on moult strategies.

3. Staff member Niall Burton monitors over 20 Tree Pipit nests each year for his long-term study of this declining species.

Nests as well as nets Have we met before?

16% of BTO staff also contribute to NRS.

Using mist nets to sample bird populations

Reedbed species are the staple of Dave’s

purely by chance interception, as on CES,

Cranwich project, with Reed Warblers the

works only for some species (generally

stars and Reed Bunting, Moorhen and

smaller ones) in some habitats (generally

Coot the supporting cast. More challenging

those with taller vegetation). Retrapping

is Niall Burton’s long-term volunteer study

Adults for Survival (RAS www.bto.org/

on Tree Pipit, one of the nation’s wariest

ras) projects often employ colour-rings,

species at the nest, a particular issue given

enabling birds to be identified individually

the absence of cover for the observer

from a distance and their progress

on the birds’ favoured clear-fell habitat.

followed. Colour-rings must be easily

Not to be outdone, Ian Henderson and

viewed if sufficient data are to be collected

Greg Conway scour the same patches for

and this technique can be particularly

Nightjar nests, a barely perceptible scrape

effective in towns, where birds are close

at which activity is limited to the hours

and habituated to people, as Allison Kew

of darkness! All nestlings found as part

and Lee Barber have both demonstrated

of these projects are ringed, making any re-encounter particularly valuable as their

3

exact age and origin are known.

A year-round pursuit Fieldwork doesn’t end with the summer, either. Greg, Allison, Lee and Graham Austin are all involved with projects exploring annual variation in moult behaviour, primarily of finches, which necessitate catching birds in autumn and winter between Thetford and Brandon; exchange of birds between their sites also provides information on foraging ranges and strategies.

Things are about to get busy and our demographic volunteers are on tenterhooks. Will bird numbers be up after a productive breeding season? Will this cold snap delay breeding? We look forward to comparing notes over the coming months!

2 015 | BTO Volunteer Magazine

19

Wo r k i n g i n pa rt n e r s h i p s

The butterflies and Since 2009, BTO, Centre for Ecology and Hydrology (CEH) and Butterfly Conservation (BC) have been working in partnership to monitor butterfly species across the UK. In 2014, 700 volunteers contributed to the survey, covering 831 randomly allocated 1-km squares. Of these squares, 44% were surveyed by BBS volunteers on BBS squares. BBS Organiser Sarah Harris says “Thank you!” and updates us on recent results.

2

Some of our BBS volunteers carry out their

of the scale, Adonis Blue, Brown Hairstreak

Research using these data at a 1-km

BBS surveys for birds as normal and then

and Purple Emperor were recorded just once,

square scale focused on the abundance

revisit the square a minimum of twice more

a rare treat for some BBS volunteers. There

and community structure in birds and

in July and August to record the butterflies

is also the option of recording moths and

butterflies on BBS squares, as well as

for the Wider Countryside Butterfly Survey

dragonflies during the WCBS visit: the most

looking at this in relation to habitat and

(WCBS).

widespread moth was the Six-spot Burnet

latitudinal data.

From this information, the following

Looking at the 2014 WCBS data from

and, living up to its name, the Common

BBS squares alone, Meadow Browns were

Darter dragonfly was seen on the highest

community measures can be assessed:

recorded in the highest number of squares –

number of BBS squares.

Species richness – total number of

253 of the 362 BBS squares surveyed – and

But what has the WCBS carried out on

species recorded in each visit;

were also at the top of the table for having

BBS squares told us about the birds and

Evenness – how different the abundances

the highest abundance. On the other end

the…butterflies? We often hear how ‘birds

of species within a community are from

are good indicators of

one another. Evenness is highest when

environmental change’;

a community is not dominated by a few,

the assumption is

highly abundant species or when all

that if well-monitored

species have an equal abundance;

species are increasing,

Diversity – the function of both species

declining or stable, in

richness and evenness;

a given community

Specialisation – separating the

structure, other

generalist species from the specialists.

unmonitored taxa will

Generalists can thrive in a wider range of

be doing the same.

conditions or have a more varied diet than

Past research suggests

specialists who require a more specific

this assumption is

habitat or food source.

1

strongest at the larger

20

At a fine scale, bird and butterfly

scales. What about

richness, diversity and specialisation

when we look at

displayed the same trends. In these cases

the finer scale? Cue

the assumption that if well-monitored

BBS and WCBS data!

species are increasing, declining or stable,

BTO Volunteer Magazine | 2 015

work together:

the Birds

In celebration of our work together:

JOIN 2-for-1 JOIN

2-for-1

3 in a given community structure, other unmonitored taxa will be doing the same does apply. At a large scale, latitude and habitat type did affect the community measures but, for richness and diversity, the relationship between

1. Meadow Brown This widespread and common butterfly topped the list of most frequently enountered species during WCBS surveys.

Butterfly Conservation AND BTO membership Butterfly Conservation for just £30

AND BTO membership With a single payment to for just £30 www.bto.org/birdsandbutterflies

or by calling 01842 750050 you will receiveWith TWOa single memberships payment for to www.bto.org/birdsandbutterflies the remainder of the year with all the or by calling 01842 750050 benefits each offers you will receive TWO memberships for the remainder of the year with all the benefits each offers

birds and butterflies remained strong.

The assumption that population trends of well-monitored species will be reflected in other taxa is supported for common and widespread species but not for rare and specialised ones. Conservation responses for priority species are, therefore, unlikely to benefit other species of conservation

Northeastwildlife.co.uk/Luke delve/david tipling davidtipling.com

concern, unless their declines have common causes.

This study suggests applying this principle at a finer scale to assist with understanding the drivers of biodiversity change, informing landowners and conservation at individual sites.

Finally, thank you to all the fantastic BBS Regional Organisers who manage the survey locally and to the BBS volunteers themselves. To find out more about the BBS or adding the Wider

2. Swallowtail is a scarce and localised species in England, but occurred on one WCBS square.

Unfortunately, the number of squares countrywide was still not high enough to pick up the influx of European Swallowtails on the south coast.

Offer available for available for new newOffer members of each membersonly of each organisation andorganicloses on sation only and closes on 31 31May May2015.

2015.

After 31 December After 31 December 2015 2015you youwill willbe beasked asked independently independently bybyboth although bothcharities charitiesto to renew renew although thereisisno noobligation obligation to do so. there so.

3. BBS Volunteer Taking on a WCBS square on your BBS square is a possibility, and 360 BBS surveyors chose to make return summer visits to their squares for this reason.

Countryside Butterfly Survey to your BBS square, please visit www.bto.org/bbs, or contact us at bbs@bto.org.

BTO Registered Charity no. 216652 (England & Wales) no.

SC039193 (Scotland). Butterfly Conservation Registered Charity 254937 Charity (Englandno. & 216652 Wales) no.

SC039268 (Scotland) BTO no.

Registered (England & Wales) no.

SC039193 (Scotland). Butterfly Conservation Registered Charity no. 254937 (England & Wales) no. SC039268 (Scotland)

2 015 | BTO Volunteer Magazine

Butterfly Conservation_Vol_ad.indd 1

21

03/03/2015 14:30:03

C o lo n i a l Wat e r b i r d s

Heronries Census goes online When observers for the first national survey of heronries posted their nest counts to Max Nicholson back in 1928 they could hardly have imagined that the survey would become an annual one and, nearly ninety years later, be entering another exciting new phase.

John Marchant reports.

In the 1930s only a few dozen people made

Little Egrets were UK rarities until the 1980s

Census counters. Spoonbill, Cattle Egret and

annual counts but the Heronries Census has

and unrecorded as breeders until 1996!

feral Night-herons have also nested among

grown in popularity and now covers at least

Since then they have become widespread

Grey Herons and been counted for the

60% of all UK heronries each year. Except

residents with a rapidly growing population.

survey and around 10% of inland Cormorant

for the periodic ‘Heronries Surveys’, in which

Most joined in with existing colonies of Grey

colonies are at sites also occupied by Grey

special efforts were made to count heronries

Herons and have been reported by Heronries

Herons. Coverage of all these colonial

nationwide, the survey kept a relatively low profile throughout its early history – operating

700 700

early 1990s and the Heronries Census emerged

600 600

as a full member of the BTO’s family of annual

500 500

300 300

enables monitoring of Grey Heron populations

200 200

not just for the UK but also for the three British

100 100

concept of the Heronries Census as a singlespecies survey: it’s hard to contemplate that

22

2012 2012

2008 2008

2004 2004

2000 2000

1996 1996

1992 1992

1988 1988

1984 1984

1980 1980

1976 1976

1972 1972

1968 1968

1964 1964

developments put paid to the original

00

1960 1960

In parallel, extraordinary avian

1956 1956

countries separately, with ever-greater precision.

1952 1952

especially in Northern Ireland and Scotland, now

400 400

1948 1948

regional network. Growing volunteer support,

1944 1944

monitoring surveys, organised through our

1940 1940

BTO resumed allocating staff time to it in the

800 800

1936 1936

for many years by expert volunteers.

900 900

1932 1932

data from relatively few counters, marshalled

1928 1928

mainly in England and Wales and receiving

FIG 1. Number of heronries counted. Coverage of UK heronries has increased greatly, boosted by periodic ‘Heronries Surveys’, in which special efforts were made to count heronries nationwide.

BTO Volunteer Magazine | 2 015

C o lo n i a l Wat e r b i r d s

FIG 2. Data are entered for each visit separately, along with the ‘year’s best estimate’ (YBE) of apparently occupied nests of each of the species.

FIG 3. Observers are encouraged to record the location and extent of colonies at fine scale. They can provide one or more editable polygons that relate to a particular year.

but are the product of data collection

explicit data entries of zero, which are not

across a whole breeding season. Sites are

recorded for other BTO online surveys.

david tipling davidtipling.com

chosen not randomly (as in BBS) nor by observers (WeBS, BirdTrack) but by the birds

Heronries online

themselves. Especially in forestry, nesting

The pages for the online survey are not fully

areas can shift over time, while remaining

realised as I write but are due for launch in April.

recognisably the same colony. Outrageously, it

Some previews are presented above.

is still the case that some of the nesting sites

The 2015 Heronries Census season has

herons choose are vulnerable to persecution:

started as normal, with Regional Organisers

access to lists of heronry locations therefore

distributing cards to observers. Counts can

needs to be restricted. On the other hand,

be returned in any format but we are hoping

we wish to open the survey more widely

for a strong take-up of the online system.

waterbirds has become integral to the

to members of the public, who might have

Data that reach us in the post or by email

survey’s role. Should ibises start to nest, they

access to land holding heronries as yet

will be input online. There is no intention to

would be covered by the Heronries Census,

unknown to the survey or could provide

phase out the cards – of which a new batch

but bitterns, Purple Heron and Great White

valuable help with the early reporting of newly

has just been printed!

Egret, that mostly nest singly, are not.

established heronries.

This year’s heron nesting season is already well under way. Soon, the Heronries Census will be receiving its first online submissions.

Online data input and data access, long

These difficulties have been overcome

Broadening the scope

familiar to supporters of our better-funded

by introducing features new to BTO online

There is much overlap between survey

surveys, has however not been available

survey design, such as a more versatile

requirements for herons and for other

for the Heronries Census. We are happy to

mapping tool and a new way for Regional

birds that nest in colonies. For this reason,

announce that, thanks to a generous legacy,

Organisers to allocate sites. While visit

the Heronries Census, with its range of

in 2015 the Heronries Census joins the BTO’s

observations are entered against a date and

‘heronry’ species, is presented online as

array of online options.

time, as in other surveys, the key value for

the first and currently only module under

population monitoring – the ‘year’s best

a new, exploratory concept – the Colonial

Modelling HC data

estimate’ (YBE) – is recorded independently

Birds Recording Scheme. Thus, where

Despite the expertise of our Information

against the season as a whole. The YBE

BTO can find the necessary resources, the

Systems department in this area, designing a

defaults to the year’s highest (or only) count

field is open to add new modules under

database for an online Heronries Census has

or estimate of apparently occupied nests but

this umbrella over the years ahead where

presented a number of new challenges. There

the observer can override this, for example

observers can enter counts and YBE-style

are several reasons why approaches needed

if different nests in the colony had been

data for apparently occupied nests of other

to differ from our other online surveys.

counted on different days. The survey’s

colonial birds such as Rooks, martins, and

Regional Organisers will verify or query dated

seabirds, at home or even abroad.

Unlike all our previous online surveys,

After exceptional periods of incubation

the Heronries Census’s primary data –

counts and can adjust each species’ YBE, for

counts of nests by colony and season – do

example where additional observers have

and growth, the fledgling Heronries Census

not relate to any particular date and time,

supplied data for the same site. YBE requires

is starting to take flight!

2 015 | BTO Volunteer Magazine

23

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