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BUTTERFLY REPORT 2018

2018 SUFFOLK BUTTERFLY REPORT BILL STONE Introduction The county butterfly report, as always, depends on the support of Suffolk’s extensive network of local recorders and dedicated foot soldiers who go the extra mile each year (literally!) to extend coverage and understanding of our species. This year is no different and I extend my thanks to all those who have provided their records, undertaken the various surveys and supported further by exploring the numerous county recording black-holes. The conservation of butterflies depends on robust, diligent and determined recording efforts and Suffolk is one of the strongest to deliver this in the UK. Some of Suffolk’s most important records come from the focused and long-term surveys such as those run and overseen by the UK Butterfly Monitoring Scheme (UKBMS). These include transects and the 1km squares of the Wider Countryside Butterfly Scheme. On a local level, both of the UKBMS require local management and I am incredibly grateful to Twm Wade, Suffolk’s UKBMS Coordinator for his diligence and doggedness in maintaining the level of recording undertaken. This is not an easy role and requires constant engagement, communication and guidance to a network of nearly 75 recorders. Having just read the 2018 WCBS report it is significant to see Suffolk recorders remain in the top 10 counties for recording effort in this scheme.

Please see the sections below for more details regarding the UKBMS schemes and locations in the county. Please try and get involved and support these surveys as opportunities always exist.

With the increase in on-line recording and use of social media I remain grateful to Richard Perryman for his professional management of the BC Suffolk website and the incredibly popular “Sightings” page. Richard’s efforts ensure that this page is relevant, informative and essentially, up to date. I know from contact with not only UK based butterfly enthusiasts but, also as far away as Italy, Holland and Belgium that the sightings page remains as an essential UK butterflies reference tool and gives a real feel as to what is happening in Suffolk.

Looking ahead, in 2019, we enter the final year of the current five-year recording period under the national Butterflies for the New Millennium (BNM) recording scheme. In this final year it is incredibly important to be as active as possible in exploring our county further and recording the butterflies seen. In the current 4-year period we have butterfly records for over 90% of the county so a little bit more exploring of the poorly recorded areas will be invaluable. However, if you are not able to explore the wilder and more remote parts of the county then please continue to support in any way you can. More local to home, the Garden Butterfly Survey continues to grow in popularity and the amount of garden and outdoor spaces is increasing each year. Whatever way you can record butterflies, I look forward to receiving your butterfly records for this significant final recording year and talking about this in the 2019 butterfly report.

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Overview of the UK weather in 2018 The year was warmer than average for the UK, although not as warm as 2017. May, June, July and December were all much warmer than average. It was also a relatively dry year, particularly across the north of the UK, with June a very dry month in the south. This was a very sunny year, particularly May, June and July. Notable extreme events during the year included a spell of severe winter weather in late February and early March. The Met Office issued two Red Warnings, and this was the most significant spell of snow and low temperatures for the UK since 2010. High pressure dominated the summer – the warmest for the UK since 2006, the driest since 2003 and the sunniest since 1995. Some rain gauges in southern England recorded more than 50 consecutive dry days and temperatures exceeded 30 °C fairly widely on 15 days during July and August. Nine named storms affected the UK during 2018. Storm Ali in mid-September brought very strong winds to the north and was one of the most notable early autumn storms of recent decades. Storm Callum in mid-October brought persistent heavy rain to western areas, especially south Wales.

The UK mean temperature for 2018 was 9.5 °C, which is 0.6 °C above the 19812010 long-term average, ranking as the seventh warmest year in the historical UK series from 1910. All top-ten warmest years in this series have occurred this century.

Summer 2018 was equal-warmest in the UK series, with 1976, 2003 and 2006. The UK rainfall total for 2018 was 1064 mm, which is 92% of the 1981-2010 average, making this a dry year overall although not exceptionally so. However, parts of northern Scotland received only 75% of average rainfall. Southern England recorded its driest June since 1925. The UK sunshine total for 2018 was 1581 hours, which is 115% of the 1981-2010 average and making this the second sunniest year for the UK in a series from 1929, with only 2003 sunnier. East Anglia had its sunniest year on record. May was also the sunniest on record for the UK. Table: 2018 Weather for East Anglia Season Winter 17/18 Spring Summer Autumn

Mean Temp Deg C 4.3 9.7 18.0 11.5

Anomaly Deg C 0.00 0.7 1.7 0.6

Sunshine hrs 225.9 477.8 749.4 428.9

Anomaly Rainfall Anomaly % mm % 121 186.5 127 102 176.0 129 127 91.9 57 132 136.6 76

Source: www.metoffice.gov.uk.

Anomalies are measured against the 1981-2010 averages.

Residents - Winners & Losers (Annex A- Scarcity for species seen in Suffolk in 2018) The year will be remembered for the significant episodes of extreme weather. It started with the “false spring” which led to hibernating species such as Small Tortoiseshell, Peacock, Brimstone and Comma emerging from hibernation early in February & March. Immediately after, there was the protracted cold spell named by

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the media as the “beast from the east�. This effectively meant that many of those butterflies which had emerged early died with a resulting negative impact on their attempts to breed and the next generation was significantly reduced as less eggs were laid than normal. This was particularly noted with Small Tortoiseshell which for some was almost a rarity in 2018. Based on records received this species was only seen in 45% of the surveyed tetrads whereas in 2017 it was seen in over 60% of surveyed tetrads. It is a species in serious decline and has lost three-quarters of its UK population since the 1970s. Its absence was most noticed during the Big Butterfly Count (England) where it suffered its worst count on record being down by 40% on 2017.

However, later emerging Spring species such as Common Blue, Brown Argus, Small Heath and the whites all appear to have benefitted with adults emerging into the warm spring and with immediate access to nectar sources and their larval food plants.

This generated strong first broods and helped with later broods. However, as the year moved on the prolonged sun and very warm temperatures started to have a negative effect on some species with numbers of very small individuals noted. This has been particularly evident with Common Blue, Small Heath, Holly Blue and Green-veined White. This is the consequence of both poor development and growth as a caterpillar due to parched food plants and the impact of hot temperatures on pupation. This negative phenomenon may also account for dips in numbers seen in grassland species such as the Essex Skipper, Small Skipper and particularly Large Skipper along with Ringlet, Gatekeeper and Meadow Brown.

On a positive note, woodland-canopy species all appear to have done reasonably well and from records received seem to be much more widely distributed. This position seems to have been possible due to the settled late spring and the slow warm up into the summer coinciding positively at key points of life cycles. The hot dry weather also encouraged adults out of the canopy resulting in them being easier to see. This resulted in both Purple and White-letter Hairstreak being seen in almost twice as many tetrads as in 2017. Of note, however, is the increase in numbers of Purple Emperor seen with this species being noted in an additional 11 tetrads based on 2017 levels. The Silver-washed Fritillary continued its slow colonisation of the county increasing its tetrad count by 9 on 2017, however, it was only a very average year for White Admiral.

The most abundant species seen was Red Admiral at 5th position this despite a significant fall in numbers on 2017 totals, Gatekeeper at 4th, Meadow Brown at 3rd, Large White at 2nd and the Small White in 1st position. Of note, Large and Small White were seen in 75% of the tetrads surveyed.

2019 may be too soon to judge the consequences of the extreme weather events of 2018; it will probably be 2020 before the real impact is understood, both for Suffolk and the wider UK. That said the long-term trends remain of concern in that two thirds of the UK butterfly species show negative abundance trends and 21 of these species show significant decreases.

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Early & Late (See Annex C- Suffolk Butterfly Species Earliest and Latest dates up to end 2018).

A review of Annex C provides for first and last records reported for each species seen in the year. This information sits alongside the Earliest and Latest dates recorded for each species as county records. Earliest county dates were recorded for several species in 2018 and included Clouded Yellow (16/04), Silver-studded Blue (16/05) and Chalkhill Blue (07/07). Meadow Brown records received provided new earliest and latest dates which in turn resulted in a flight season from 7 April to 15 October which is remarkable. The latest date is almost a week later than the previous record. Other latest dates recorded were for Large Skipper (25/09), Ringlet (27/09), Holly Blue (17/11) and Speckled Wood (18/11).

It is worth noting that the UKBMS Official Statistics for 2018 report stated that the “mean flight date for the vast majority of species was earlier than the series average, with peak dates for many species advanced by a week or more. Also noted was the brevity of the season, with about two thirds of species showing a shorter flight period in 2018 than the average over both the past ten years and the whole series�. This was noted in Suffolk for many species with the early end to the season brought about by the very dry conditions and loss of larval food plants simply dried up by the heat.

Migrants In respect of migrants it was a relatively poor year for Clouded Yellow, Painted Lady and Red Admiral with numbers down by almost a third for Clouded Yellow and a quarter for both Painted Lady and Red Admiral when compared to 2017.

Maps below are for Clouded Yellow and Painted Lady for records received in 2018.

Clouded Yellow 2018

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Painted Lady 2018

The Red Admiral continues to be treated as a migrant butterfly although it is clear that it is over-wintering in increasing numbers. This species can now be seen in all 12 months of the year with a resulting small UK population being swelled by immigrants from southern Europe as shown below.

Chart: Red Admiral flight period The reduction in Red Admiral numbers seen in 2018 not just in Suffolk but throughout the UK may reflect the negative effects of the false spring and subsequent severe cold spell. Despite this short-term fall, the longer-term trend for this species is positive with an increase in abundance recorded. The 10- year trend shows a 45% increase with a 212% “highly significant� increase over the series trend (43 years).

Other migration noted and recorded during the year involved numbers of Small White and Large White seen at coastal sites along with several records of these species along with Red Admirals seen at sea off the Suffolk coast.

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Rarities As in previous years Suffolk was lucky again to experience some rare and scarce butterflies alongside the regularly occurring migrant species.

Swallowtail: Three records, all singles, for this species were received: 2 June in north-east Ipswich, 25 June at Loompit Lake, Levington 2 July at Dingle Marshes, Walberswick.

Unfortunately, none were photographed but all were seen by reliable and experienced butterfly observers. It is difficult to assign the butterflies seen, without further details or photographs, to either the continental Swallowtail (P. m. gorganus) or the “British Swallowtail� sub-species (P. m. britannicus). Of note, this species flew in Norfolk in 2018 between 15 May and 5 July.

Dark-green Fritillary: A single record of a Dark-green Fritillary was made at RSPB Minsmere on 23 June. This was photographed and remained for most of the day allowing a number of people to enjoy it. It is difficult to know the origin of this butterfly but this species enjoyed a good year in neighboring Norfolk and the butterfly was on the wing in 2018 between 18 June and 15 August. Norfolk records also showed an increase in inland sightings away from traditional northern coastal sites.

Long-tailed Blue: A single record was received of a Long-tailed Blue at Bixley Heath, Ipswich on 18 October. The butterfly was photographed which confirmed the identification and sex as female. (Of note, a male Long-tailed Blue was seen and photographed in 2017 at a nearby site in central Ipswich but in July).

Large Tortoiseshell: A single record was received of a Large Tortoiseshell around farm buildings near Mutford on 4 July. This was photographed and confirmed as this species as opposed to the similar looking, but even rarer, Yellow-legged or Scarce Tortoiseshell. It is highly likely that Suffolk hosts more Large Tortoiseshells than are being reported, this is supported by the fact that it is being seen in slowly increasing numbers in coastal SE English counties and becoming more widespread in the near continent, particularly Holland and Belgium.

Camberwell Beauty: One record was received for the year and this was reported on 5 May from a location along the River Gipping between Badley and Needham Market. A photograph was also provided although little other details are known about this sighting. As with other large butterfly species, the Camberwell Beauty, unfortunately, features in butterfly wedding releases. Singleton sightings such as this, therefore, need to be treated with caution.

Other species recorded Marbled White has been reported from a number of west and mid- Suffolk sites and these do appear to be genuine wanderers from both Essex and Cambridgeshire populations. The map below captures these records and it is hoped that over time these pioneers will help to re-establish this beautiful butterfly species in the west of the county.

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Marbled White 2018

The Marbled White also continues to fly in central Ipswich at Landseer Park and nearby at Pipers Vale, Orwell Country Park. These butterflies originate from unauthorised introductions and information received suggest that they continue to be “topped-up” on a regular basis. The whole area remains “suspect” as other “oddities” reported from this local area in 2018 include Wood White, Dingy Skipper, Adonis Blue, “yellow” swallowtails and various black (presumed North-American) swallowtail species.

Brown Hairstreak was recorded again in the Pipers Vale and Bestead areas of Ipswich both from winter egg counts and flying adults albeit in much smaller numbers than seen in recent years.

The recording position on these presumed releases of Marbled White and Brown Hairstreaks at central Ipswich sites is that they will not be submitted to Butterfly Conservation for inclusion in national data sets. However, local monitoring will be undertaken and records will be maintained at a county level in order to assess population and range changes.

Suffolk Biodiversity Action Plan- Priority Species (see also https://www.suffolkbis.org.uk/biodiversity/speciesandhabitats/specieslist) Seven species of butterfly occurring in Suffolk are deemed as UK BAP priority species.

These are Dingy Skipper, Silver-studded Blue, White-letter Hairstreak, White Admiral, Grayling, Wall and Small Heath. These are all dealt with separately in the accompanying annexes (D-J) as listed below.

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Recording and Geographic Coverage in 2018 Butterflies for the New Millennium (BNM) remains the key recording scheme for general distribution and numbers of butterflies. The BNM aims to achieve comprehensive national coverage in successive five-year recording periods.

2018 was the fourth year in the current five year (2015-2019) recording period.

Nearly, 35,000 records were received for 2018 and butterflies were recorded in 786 county tetrads (2km x 2km squares). In 2017, butterflies were recorded in 728 tetrads so 2018 actually saw records from an additional 58 tetrads. This is excellent and positively reflects my calls for additional coverage. So, overall, given that there are 1089 tetrads in Suffolk butterflies were recorded in approximately 72% of Suffolk during the year. The Suffolk coverage map for 2018 is shown below.

Number of species 2018

However, as this was the fourth year of the current five-year period it is worth noting the extent of coverage achieved over the longer term. Combining the data from 2015, 2016, 2017 and 2018 shows that over 134,000 records have been received with butterflies being seen from 1005 county tetrads. This gives us an incredible 92% county coverage which is a brilliant position to be in at the end of year four and places us in a very strong position going forward into the final fifth year. The Suffolk coverage map for 2015-2018 is shown below.

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Number of species 2015-2018

Analysis (ANNEX B- Long term trends for residents and regular visitors 1995 to 2018) The 39 species of butterfly recorded in 2018 are shown in Annex A, in order of scarcity, with a direct comparison to last year’s results. At a glance, this shows a noticeable year on year increase between 2017 and 2018 for: Purple Emperor Purple Hairstreak White-letter Hairstreak Brown Argus Silver-studded Blue Small Heath However, trends over a longer period are presented separately at Annex B for our regular species. The latest rolling 5-year figure (2014-2018) covers 1029 tetrads and shows an average of 15.6 species per tetrad. Of note, long term analysis easily shows the slow but steady spread of Silver-washed Fritillary. Other species are holding their own whereas species such as Wall is slowly declining and its range within the county is becoming restricted. Furthermore, Dingy Skipper remains at a very low level and as such remains highly vulnerable especially given significant and ongoing forestry work within the Kings Forest.

UK Butterfly Monitoring Scheme (UKBMS)- Transects Transects are very effective at monitoring habitat specialist butterflies and lowland semi-natural habitats. They are resource intensive but give a sharp view of butterfly

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trends. The 2018 results from those transects walked in Suffolk have been added to the Suffolk database and are a useful addition as they reflect consistent, sustained and focused recording within the county.

During 2018, 26 transects and 3 single species transects were monitored and these are listed below. My thanks go to all those team coordinators and walkers, who put in dedicated monitoring efforts at: Suffolk Transects: Site Name Alton Water Black Heath Center Parcs (Elveden) Dunwich Forest 1 Little Ouse Headwaters Manor Farm (Coddenham) NE Cavenham Heath Newsons Farm (Thorpe Green) Newsons Farm Ext-(Thorpe Green) Nowton Country Park Ramsey/Hintlesham Woods River Lark Path Rookery Farm, Ousden Suffolk Single-species transects: Site Name Blaxhall Common Purdis Heath SWT Bradfield Woods

RSPB Lakenheath RSPB Minsmere RSPB North Warren RSPB Wolves Wood Sizewell Belts Spring Lane (Bury St Edmunds) SWT Bradfield Woods SWT Church Farm SWT Lackford Lakes SWT Knettishall Heath SWT Redgrave and Lopham Fen SWT Reydon Wood Upper Abbey Farm (Leiston)

Species Silver-studded Blue Silver-studded Blue Purple Hairstreak

UK Butterfly Monitoring Scheme (UKBMS)-Wider Countryside Butterfly Scheme (WCBS) The WCBS complements transect monitoring of butterfly populations on semi-natural sites and forms part of an integrated approach to monitoring butterflies through the UK Butterfly Monitoring Scheme (UKBMS). It runs as a partnership between Butterfly Conservation, the British Trust for Ornithology (BTO), the Centre for Ecology and Hydrology (CEH) and the Joint Nature Conservation Committee (JNCC).

The scheme targets common and widespread butterflies by selecting random 1km squares which are then subject to a minimum of two visits ideally in July and August.

The records generated from the scheme are included in the Suffolk data set and represent a significant contribution both in terms of record numbers but also in respect of the locations involved. In 2018, records were received from the 35 squares as shown below. Disappointingly, four additional squares were surveyed but records were not submitted or lost.

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BUTTERFLY REPORT 2018

WCBS – Suffolk 2018 OS Reference Org’

Name

OS Reference

Org’

Name

TL6381 TL6545 TL7163 TL7262 TL7781

BC BC BC BC BC

West Row Haverhill Gazeley Dalham Hall Wangford

TM0871 TM1234 TM1666 TM2144 TM2147

BC BTO BTO BTO BC

TL7866

BC

Risby

TM2160

BC

TL7951

BC

TM2481

BTO

TL8161

BC

Hawkedon Ickworth (New 2018)

Gislingham Brantham Aspall Foxhall Playford Cretingham (New 2018) Shotford Heath

TM2975

BC

Cratfield

TL8271

BC

Wordwell

TM2984

BTO

St Cross, South Elmham

TL8566

BC

Fornham St Martin, Bury St Edmunds (N)

TM3150

BC

Eyke,

TL8778

BC

Barnham

TM3183

BC

TL8843

BC

Sudbury (N)

TM3388

BC

TL8862

BTO

Rushbrooke

TM3450

BC

TL9047

BC

Acton, Lavenham

TM3549

BC

TL9475 TL9859

BTO BC

TM3762 TM5075

BC BTO

TM0048

BC

TM5195

BC

Flixton

TM0553

BC

Bardwell Rattlesden Nedging-withNaughton Battisford

St Margaret, South Elmham Bungay Rendlesham Forest Rendlesham Forest Benhall Southwold

There are a large number of WCBS squares available for adoption in Suffolk and if you are interested in getting involved with butterfly surveys then please consider this type of activity aspect. The Suffolk Coordinator, Twm Wade would be very pleased to hear from you.

Annexes: Annex A Annex B Annex C Annex D Annex F Annex H Annex J

Scarcity for species seen in Suffolk in 2018 Long term trends for residents and regular visitors 1995 to 2018 Suffolk Butterfly Species Earliest and Latest dates up to end 2018 Dingy Skipper Annex E Silver-studded Blue White-letter Hairstreak Annex G White Admiral Grayling Annex I Wall Small Heath

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Annex A- Scarcity for 39 species seen in Suffolk in 2018 Tetrads per Species – 2017 & 2018 (Species listed in order of scarcity in 2018) % of 728 2017 2018 % of 786 Tetrads Tetrads Species Tetrads Tetrads 0.2 2 Camberwell Beauty 1 0.1 0 0 Dark-green Fritillary 1 0.1 0 0 Large Tortoiseshell 1 0.1 0.1 1 Long-tailed Blue 1 0.1 0.1 1 Chalkhill Blue 1 0.1 0 0 Swallowtail 3 0.3 0.9 7 Dingy Skipper 8 1.0 1.6 12 Silver-studded Blue 16 2.0 2.8 21 Wall 18 2.2 1.0 8 Purple Emperor 19 2.4 7.8 57 Clouded Yellow 38 4.8 6.3 46 Silver-washed Fritillary 55 6.9 7.2 53 Grayling 58 7.3 8.2 60 White Admiral 66 8.3 7.8 57 Green Hairstreak 67 8.5 5.2 38 White-letter Hairstreak 71 9.0 17.0 124 Essex Skipper 103 13.1 10.8 79 Purple Hairstreak 150 19.0 13.7 100 Brown Argus 174 22.1 32.4 236 Large Skipper 174 22.1 21.1 154 Small Heath 200 25.4 29.2 213 Small Skipper 201 25.5 41.4 302 Painted Lady 242 30.7 34.3 250 Small Copper 268 34.0 43.4 316 Brimstone 288 36.6 43.4 316 Orange-tip 311 39.5 37.5 273 Holly Blue 346 44.0 51.9 378 Ringlet 354 45.0 61.5 448 Small Tortoiseshell 356 45.2 63.1 460 Comma 378 48.0 42.7 311 Common Blue 395 50.2 51.9 378 Speckled Wood 416 52.9 48.3 352 Green-veined White 433 55.0 69.3 505 Peacock 461 58.6 75.5 550 Red Admiral 469 59.6 65.5 477 Gatekeeper 475 60.4 66.8 487 Meadow Brown 492 62.5 71.9 524 Large White 589 74.9 68.9 502 Small White 607 77.2

*cf last 0.5 0 0 1.0 1.0 0 1.11 1.25 0.78 2.4 0.61 1.09 1.01 1.01 1.08 1.73 0.77 1.75 1.61 0.68 1.20 0.87 0.74 0.99 0.84 0.91 1.17 0.86 0.73 0.76 1.17 1.01 1.13 0.84 0.78 0.92 0.93 1.04 1.12

*cf last- Indicates change against last year’s coverage when compared with current year.

Note 1: Swallowtail includes P. m. britannicus and P. m. gorganus Note 2: Marbled White and Brown Hairstreak not included in comparison.

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Annex B. ANALYSIS - 2008 to 2018 Long term trends - for residents and regular visitors.

Survey from: to:

2008 2012

2009 2013

2010 2014

2011 2015

2012 2016

2013 2017

2014 2018

Period: Tetrads:Species/Tetrad:

5yrs 993 13.8

5yrs 998 14.3

5yrs 1023 14.2

5yrs 1025 14.6

5yrs 1006 14.8

5yrs 1008 15.3

5yrs 1029 15.6

Small Skipper Essex Skipper Large Skipper Dingy Skipper Clouded Yellow Brimstone Large White Small White Green-veined White Orange Tip Green Hairstreak Purple Hairstreak White-letter Hairstreak Small Copper Silver-studded Blue Brown Argus Common Blue Holly Blue White Admiral Red Admiral Painted Lady Small Tortoiseshell Peacock Silver-washed Fritillary Comma Speckled Wood Wall Grayling Gatekeeper Meadow Brown Ringlet Small Heath

422 283 475 7 69 450 832 811 765 612 119 178 76 417 20 279 513 500 93 750 537 687 714 37 694 740 96 104 732 816 634 271

425 280 510 10 166 479 840 833 761 604 109 213 79 440 20 296 556 494 101 738 580 762 760 52 717 727 81 106 763 824 662 288

No. tetrads recorded 468 293 537 9 187 515 841 861 762 650 128 215 81 453 19 290 557 488 113 789 419 812 794 65 717 727 75 117 782 843 680 302

491 317 573 9 199 542 856 855 750 652 139 209 83 453 21 276 557 503 111 802 518 829 829 77 740 740 74 124 801 851 703 305

486 324 555 9 221 558 856 855 718 604 117 209 88 449 22 243 539 493 123 799 557 821 840 81 737 709 64 131 791 861 723 303

508 336 566 9 245 590 881 880 737 632 130 216 96 473 22 263 591 524 128 837 602 847 871 98 757 714 69 132 811 862 724 314

513 334 547 10 196 612 919 912 759 667 148 248 122 501 24 319 641 581 143 868 601 851 886 113 764 736 67 139 831 870 729 357

NB: Rarities excluded.

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Annex B. ANALYSIS - continued Annual figures Survey

2013

2014

2015

2016

2017

2018

Period: Tetrads:Species/Tetrad:

1yr 640 10.9

1yr 736 10.9

1yr 710 11

1yr 677 10.2

1yr 728 11.1

1yr 786 10.5

Long Term Trend

201 103 174 8 38 288 589 607 433 311 67 150 71 268 16 174 395 346 66 469 242 356 461 55 378 416 18 58 475 492 354 200

Stable Stable Stable Weak and vulnerable Migrant: variable Stable, slowly increasing Stable Stable Stable Stable Weak but Stable Stable Weak but Stable Stable Weak and vulnerable Stable Stable Stable Stable Migrant: variable Migrant: variable Recovering Recovering Slowly colonising Stable Stable Slow decline Stable but vulnerable Stable Stable Stable Weak and vulnerable

No. tetrads recorded Small Skipper Essex Skipper Large Skipper Dingy Skipper Clouded Yellow Brimstone Large White Small White Green-veined White Orange Tip Green Hairstreak Purple Hairstreak White-letter Hairstreak Small Copper Silver-studded Blue Brown Argus Common Blue Holly Blue White Admiral Red Admiral Painted Lady Small Tortoiseshell Peacock Silver-washed Fritillary Comma Speckled Wood Wall Grayling Gatekeeper Meadow Brown Ringlet Small Heath

181 104 240 7 131 236 490 467 363 232 27 83 25 194 15 84 273 187 51 290 222 476 462 31 389 343 24 59 414 451 338 131

252 131 268 5 95 281 508 503 388 337 58 62 22 204 14 109 285 144 55 500 204 574 573 33 407 424 36 70 465 502 354 142

NB: Rarities excluded.

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234 126 269 4 32 278 556 527 348 284 58 66 32 195 15 96 267 276 61 450 354 471 510 37 407 341 22 59 478 498 357 122

182 103 204 5 49 273 465 475 359 289 39 65 38 178 15 84 188 271 57 469 264 375 458 29 344 321 18 61 384 430 350 104

213 124 236 7 57 316 524 502 352 316 57 79 38 250 12 100 311 273 60 550 302 448 505 46 460 378 21 53 477 487 378 154

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BUTTERFLY REPORT 2018 Annex C – Earliest and Latest dates for Suffolk Butterflies (at end of 2018) Recorder Mervyn Bell W. E. Lemmon Stuart Ling Jenny Bradin Mervyn Crawford Kerry Reeve BTO Garden Survey Graham Peck Eileen Coe Sue Cox SWT Lackford Reg Etheridge David Dowding Linda Hammond Twm Wade Meg Johnson Michael Dickens Terry Peake Mike Dean Brian Thompson Two records Multiple records Ian Barthorpe Multiple records A & E Beaumont Stan Dumican Reg Etheridge Tony Prichard Mervyn Crawford Peter Smith Rose Andrews Reg Etheridge Mervyn Crawford Christine Williams Twm Wade

Earliest 28 May 97 25 Apr 90 29 May 83 05 May 17 20 May 17 16 Feb 15 16 Feb 14 03 Feb 17 11 Mar 00 16 Apr 18 02 Jan 14 01 Apr 09 10 Mar 15 22 Apr 17 24 May 17 07 Apr 18 20 Mar 14 12 Jun 14 13 Jun 17 06 Jun 14 23 Jun 14 1 Jan 04/01/16 1 Jan 01/01/00 15/01/95 20 Mar 10 03 Jun 13 30 Mar 17 30 May 15 16 Mar 17 16 May 18 24 Apr 04 06 Apr 17 07 Jul 18

Species Swallowtail Dingy Skipper Essex Skipper Small Skipper Large Skipper Orange Tip Large White Small White Green-veined White Clouded Yellow Brimstone Wall Speckled Wood Small Heath Ringlet Meadow Brown Gatekeeper Grayling Silver-w Fritillary White Admiral Purple Emperor Red Admiral Painted Lady Peacock Small Tortoiseshell Comma Small Copper Purple Hairstreak Green Hairstreak White- l Hairstreak Holly Blue Silver-studded Blue Brown Argus Common Blue Chalkhill Blue

Latest 28 Aug 91 12 Jul 17 14 Sep 16 25 Sep 95 25 Sep 18 21 Jul 13 25 Dec 11 19 Nov 06 05 Nov 06 21 Nov 32 28 Dec 15 30 Oct 95 18 Nov 18 10 Nov 11 27 Sep 18 15 Oct 18 06 Oct 05 01 Oct 06 03 Oct 14 17 Oct 14 26/08/12 31 Dec 06 20 Nov 95 31 Dec 28 Dec 14 Dec 16 16 Nov 94 27 Sep 15 23 Jul 14 11 Sep 17 17 Nov 18 30 Sep 07 27 Oct 08 06 Nov 94 28 Sep 15

Recorder Ian Porter Jenny & Gary Plank George Millins Stella Wolfe Debs Crawford Ray Hardinge Dave Langlois Stuart Gough Will Brame Mr Richardson Mick Saunt Betty Serjeant Will Brame Reg Etheridge Ray Hardinge Lydia Calvesbert Lydia Calvesbert Steve Goddard David Dowding Paul Collins Julian Dowding Nick Dickson Colin Hawes Multiple records Multiple records Melvyn Eke Richard Stewart Dudley Sheppard Richard Perryman Bill Stone Bill Stone Richard Havard Nigel Odin Two records Twm Wade

The names and taxonomic order of species follow the new checklist: Agassiz, D., Beavan, S.D. & Heckford, R.J. (2013) A checklist of the Lepidoptera of the British Isles. Royal Entomological Society, St Albans.

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Annex D-Dingy Skipper The Dingy Skipper was first seen in Suffolk in the Kings Forest on 6 May a week later than in 2017. The butterfly was last recorded, again in the Kings Forest, on 28 May with 8 seen flying in the Archery area and it seems reasonable to assume that the butterfly flew well into early June.

The following is a summary of the survey work undertaken and sites visited.

Surveys again focussed on the Kings Forest, NWT Thetford Heath, RAF Barnham and other key sites within the Suffolk Brecks. A good number of casual records were also received during the month on May to complement the planned surveying.

Location

Grid Reference

Date

Kings ForestChalk Lane Kings ForestChalk Lane Kings ForestWordwell Kings ForestChalk Lane North of West Stow Kings ForestWordwell + west of B1106 NWT Thetford Heath Angles Way/ Marmansgrave Wd RAF Barnham Kings ForestWordwell Kings ForestWordwell

TL8275/8374/ 8375/8474 TL8275/8374/ 8375 TL8473

13/05/2018

Max No. of Dingy Skippers recorded Nil

15/05/2018

1

15/05/2018

8

TL8275/8374/ 8375 TL8072 TL8273/8372/ 8373/8473/ 8274/8374 TL8480/8580 TL8480/8481

17/05/2018

1

18/05/2018 19/05/2018

1 26

19/05/2018 19/05/2018

Nil Nil

TL8580/8680 TL8273

20/05/2018 20/05/2018

12 12

TL8273/8372/ 8373/8473/ 8274/8374 TL8681

23/05/2018

75

Barnham Cross 23/05/2018 1 Common Elveden TL8080 24/05/2018 2 West Stow TL8174 24/05/2018 4 Given the casual records received and survey results it is clear that the butterfly flew in reasonable numbers throughout May in the Kings Forest. Additional effort was put into extending coverage within the Kings Forest and this paid off with sightings made along the eastern fringes, to the west of the B1106 and to the south near West Stow village.

Disappointingly, and for the second year running it was not recorded at NWT Thetford Heath despite a thorough search. However, the lack of Birds-foot Trefoil and Trans. Suffolk Nat. Soc. 55 (2019)

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poor grass habitat may have something to do with this. The butterfly was seen again in good numbers on MOD land at RAF Barnham with several copulating pairs observed. Of particular note was a record of 2 Dingy Skippers seen during a survey of the Elveden Center Parcs wildlife mounds. This is significant as the butterfly has not been recorded here since 2014.

Based on the records received in 2018 the distribution map below identifies the small area that the Dingy Skipper continues to cling on to in the Suffolk Brecks. In 2018, it was recorded in 8 tetrads, 1 more than in 2017 which is positive.

Dingy Skipper 2018

The Kings Forest remains the stronghold for the species in the county and numbers seen this year were pleasing. It is also significant that the butterfly appears to have spread, albeit in small numbers, to other parts of the forest away from the favoured Wordwell and Chalk Lane areas.

The butterfly has demonstrated its robustness and its ability to move short distances within the forest to colonise newly cleared areas especially where birds-foot trefoil can be found. However, given the significant forestry activity seen along with ongoing activity the species’ position continues to hangs in the balance and requires constant monitoring.

On a national basis the UKBMS Summary of Changes table show the Dingy Skipper was recorded as having an above average year with a 10% increase on 2017 records.

That said, it remains of concern with a -18% decrease over the 10-year trend and 22% over the long-term series trend (43 years).

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Annex E- Silver-studded blue

By D. Dowding and H. Saunders Despite the cold spring, the persistently hot summer gave rise to an early emergence of Silver-studded Blues, with the first butterflies recorded on the surveyed sites on 4 of June, just 3 days later than the early emergence in 2017 and 9 days earlier than the 10-year average. The counts were significantly higher than 2017, but the flight season was considerably shorter. The lack of moisture and persistent heat caused a very sudden emergence over a shorter period. The peak came just 10 days after first emergence (14th) and tailed off by the end of June.

Silver-studded Blue 2018

The geographical range has changed slightly in the last 10 years with some colonies lost and some gained, but the core populations remain the same. The newer satellite colonies at the Martlesham Common and Piper’s Vale sites are slowly increasing into double figures as funding and appropriate management is allowing more pioneer heathland to be created through turf stripping, seeding, bracken control and mowing.

Population counts The Peak counts in 2018 were very promising, with the majority of sites matching or bettering the 2006 datum year. The ratio of males to females across the county was 5:1 due to the narrower window of emergence. The total Suffolk count of 5990 was 4.5 times larger than last year’s count with most sites significantly higher than normal.

This matches the datum year of 2006. It must be noted that lack of rain and persistent

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hot weather caused a narrower window of emergence, so counts would have been less representative than compared with normal years meteorologically.

We were back up to 26 counts this year with committee members taking on some of the RSPB Minsmere transects although there are still parts that need monitoring.

Silver-studded Blues are no longer as abundant as they once were in many areas at RSPB Minsmere such as the gravel pits and the reversion field. This is because the heather in these areas has aged significantly. The butterflies have, however, spread into new areas. New heathland regeneration areas in Dunwich Forest have shown a good return of numbers where clear felling of 16 acres of coniferous woodland and the implementation of grazing has created conditions for pioneer heather and birdsfoot trefoil to flourish, plants which are both a good nectar source and suspected larval foodplants.

Overall, 2018 was a very good year for the butterfly and it will be interesting to see how well the populations do in 2019. Will they kick off from here or will the generally downward population decline trends in Suffolk continue. The key factor in population strength is the area of good quality habitat. Heathland, is such a dynamic habitat and keeping it in a pioneer state requires lots of input from livestock/machinery and human interventions. Ongoing maintenance and recreation of pioneer heathland communities is vital in the species success and the lack of input is often what causes the butterfly do disappear. The greater the data set tabulated each year, the greater the comparability and the more trends can be analysed. To help with this we are always looking for volunteers, both for practical conservation work and for population monitoring. Recent effort has proved that dedicated habitat management can help the butterfly recover and every year we are learning more about the specie’s ecology.

If you are interested in helping please contact Helen Saunders – details in the Suffolk Argus or on Suffolk Branch website: http://www.suffolkbutterflies.org.uk Annex F- White-letter Hairstreak In 2018, the butterfly was first recorded on 22 June (Northfield Wood, Onehouse and Bramford Road Allotments, Ipswich) and last recorded on 8 August (Wangford Warren). In previous years most reports related to single butterflies but in 2018 there were many low double figure counts made. Some very high counts were also made and these are worth highlighting as below: 23 June- Battisford- 75 25 June- Euston Drove- 40 29 June- A14, Trimley St Martin- 71 The map overleaf shows the recorded coverage for the year with the butterfly being recorded in 71 tetrads. This is almost double the 38 tetrads in which the butterfly was seen in 2017. This significant increase clearly reflects a successful year for this species no doubt helped by the warm summer. There was much comment from recorders as to how easy to see this butterfly was to see in 2018. Several new sites were discovered during the flight season and the butterfly was encountered in habitats away from elm trees including gardens, parks and rail and road embankments.

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T. Goodfellow

White-letter Hairstreak 2018

Within the county, the long-term trend (see Annex B) is still of concern with no real significant increases noted and I have described the White-Letter Hairstreak population as being “weak but stable�. On a national level, the UKBMS Summary of

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Changes table 10-year trend indicates a fall of -40% in abundance. This is better than last year’s figure of -59% and reflects the better season enjoyed by this species this year. From a long-term position, this species is described as suffering from a “very highly significant” fall in abundance based on the UKBMS 1976- 2017 trend period which reveals a fall in White-letter Hairstreak abundance of -92%.

The White-letter Hairstreak remains a troublesome butterfly for recording purposes. Seeing the butterfly and accurately addressing the population of this species is difficult due to it invariably flying in the canopy of elms and neighbouring trees. It can also roam wide areas utilising elm hidden amongst roadside hedgerows.

It is, therefore, difficult to count away from known sites where established viewing positions are normally used. As identified above, locating additional sites is important for the future assessment of this species. Looking for elms in the spring is a useful method as they often get lost amongst other more dominant trees as the canopy develops. These sites can then be recorded and returned to in the summer for accurate monitoring.

Annex G- White Admiral The White Admiral was recorded in 66 tetrads as opposed to the 60 in 2017.

However, this species did not see the significant increases in numbers as seen with Purple Emperor and Purple Hairstreak. The map below shows the distribution of the species in the county in 2018.

White Admiral 2018

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Chart: White Admiral generations 2018

A number of double figure counts were made with over 40 butterflies being reported during visits to Assington Thicks and SWT Bonny Woods in late June but most records were low single figures. As in recent years, despite being a butterfly of mature deciduous woodlands, a number of records and photos received for this species concerned individuals seen in gardens and urban sites. This reinforces the fact that it is a strong flyer prone to wandering after breeding and seeking out new territories.

Despite the species appearing to be stable in the county, albeit, in low numbers the national position is very different. The UKBMS Summary of Changes table 10-year trends indicate a -31% fall in abundance. As with the White-letter Hairstreak, the White Admiral is also described as suffering from a “very highly significant� fall in abundance based on the UKBMS 1976- 2017 trend period which reveals a general fall in abundance of -70%.

Annex H- Grayling In 2018, the Grayling was recorded in 58 tetrads as opposed to the 53 in 2017 which is a slight increase although still disappointing given the increased county coverage. It was first seen on 18 June at Newbourne. It was last seen on at 25 September at Upper Hollesley Common. Some reasonable counts were made with many 50+ counts received. The highest count made, however, related to 99 seen at RSPB Minsmere on 20 July and then 113 seen again at RSPB Minsmere on 30 August.

The map opposite shows the distribution recorded in the year and clearly shows the county divide and is representative of the Breckland habitat in the east of the county and the Sandlings habitat in the east. It sharply represents this species’ preference for dry sandy grasslands. As with previous years a few wanderers were recorded away from key sites in gardens and parklands indicating that this species is capable of finding new sites and will exploit them if suitable. A number of records of Graylings in urban gardens made reference to nectaring on buddleja and in a couple of cases the butterflies were seen vigorously defending the buddleja against other butterflies.

As with the Dingy Skipper, the Grayling was noted to have had an above average year in 2018 and much better than in 2017 which from a national perspective was its worst year on record. The UKBMS Summary of Changes table shows that it remains of concern with a -67% decrease over the 10-year trend and a highly significant -73% over the long-term series trend (43 years).

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Grayling 2018

Annex I- Wall The Wall was first recorded in 2018 on 10 May at SWT Carlton Marshes some two weeks later than in 2017. It was last seen on 25th October again at SWT Carlton Marshes. The best counts received were all from SWT Carlton Marshes with the highest being 12 on 28 May. Most records received away from SWT Carlton Marshes were of single butterflies. A review of all the records received helps to identify the generations seen within the county. The graph below helps to show the first (10 May to 11 June) and second (28 July to 19 August) generations both being almost two weeks later than those seen in 2017. A relatively strong third generation was noted (17 September to 25 October), a week earlier than the 2017 3rd generation.

Chart: Generations of Wall, 2018 The Wall was, disappointingly, only recorded in 21 tetrads in 2017, albeit slightly up on 2016 where it was recorded in 18 tetrads. The distribution map overleaf shows where the Wall was recorded.

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Suffolk Natural History, Vol. 55 Wall 2018

It has continued its slide eastwards towards the coast and is now only recorded in two key locations; the area comprising of Orford/ Sudbourne and sites within the Waveney Valley. The key site for the whole county is now SWT Carlton Marshes. It is worth acknowledging the recording effort of volunteer warden Robert Quadling who has championed efforts to accurately record the Wall across this site and raise its profile to visitors to the reserve.

Of interest, some Wall sightings were also made by experienced recorders in the south-west of the county and coastal records were made at Shotley and Landguard Common. This may suggest that small, remote populations still exist in suitable habitat or are indicative of wandering individuals.

Sadly, the Wall continues its decline in Suffolk and this position is reflected throughout the UK and parts of Europe. The UKBMS Summary of Changes table shows the long-term series trend (1976-2017) as -88% decline. As such, this decline is classified as "very highly significant". It is, therefore, essential that the county population is monitored very closely and both range and abundance recorded accurately.

Annex J- Small Heath The Small Heath was recorded in 200 tetrads this year which represents an astonishing increase when compared to the 154 achieved in 2017. The first record was received on 5 May at NE Cavenham Heath. It was last reported on 17 October at Landguard Common, Felixstowe.

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The maximum numbers recorded for the year was 63 at Landguard Common on 23 June and 68 at SWT Knettishall Heath on 4 July. Elsewhere, high double-figure counts (50+) were recorded at key sites in both the east and west of the county.

The distribution map below clearly shows the strongholds of this butterfly as the heaths of the Sandlings in the east of the county and of the Brecklands to the west.

However, in 2018 the butterfly was seen in many new areas including, parks and gardens reminding us that it is highly adaptive and can be found in a variety of grassy habitats.

Small Heath 2018

The increase in the Suffolk population in 2018 is very pleasing and relates to the favourable weather in the spring and early summer which allowed the butterfly to breed successfully and establish strong subsequent generations. However, we cannot be complacent as the long-term trend for Suffolk is still “weak and vulnerable” and this is mirrored in the UKBMS Summary of Changes Table for 2018. This identifies a series trend (1976-2016) of -54% for the Small Heath population and this fall in abundance is classified as being “very highly significant”.

Bill Stone 26 Thomas Crescent, Kesgrave IP5 2HN butterfly@sns.org.uk

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