The Suffolk Argus
Special Edition - Summer 2008
Suffolk Argus The
The Newsletter of the Suffolk Branch of Butterfly Conservation
STOP PRESS On 20 June 2008, David Mason (SWT) saw the first Silver-studded Blue that proved that eggs had been laid and that the insects had survived their first winter. Soon after, volunteers walking the transect found numbers rising, and by 4 July, each transect walk was seeing a dozen or more. The peak count was on 13 July, when Terry Peake counted 9 males and 5 females. The butterflies were mostly flying in the immediate vicinity of the release points, but several were also seen in Section 5, near the stump, about 100m west of the former travellers site at the start of Section 7. This number of sightings on a daily basis might reflect a population of about 45 in total, rather less than the 60 released in 2007, but a satisfactory start nonetheless. This initial success was duly reported in the East Anglian Daily Press, and the Times carried a paragraph by Simon Barnes celebrating the remarkable life style of the Silver-studded Blue and its attendant ants. Visits to the donor sites found satisfactory numbers flying at Lower Hollesley Common, and Minsmere Sawmills, so there is no immediate concern that the translocation has had a significant impact on the donor colonies. Re-establishment attempts often produce a successful showing after one year, only to fade out over the next 2 or 3 seasons, so there is no reason to reach for the champagne yet.
Silver-studded Blue by Malcolm Farrow
The translocated Silver-studded Blues settled in their new habitat at Blaxhall Common.
Report on 2007 Translocation of Silver-studded Blue, Plebejus argus to Blaxhall Common, Suffolk Summer 2008
Special Edition
The Suffolk Argus
Special Edition - Summer 2008
Contents
Distribution of this report:
Covering letter
3
Record of Re-establishment proforma
4
Report on 2007 Translocation
6-12
Blaxhall Common map
10/11
Natural England (6)
The role of Ants
13
Invertebrate Link (6)
Targets for Success
14
Butterfly Conservation Head Office (6)
Codes & Guidance
15
Suffolk Branch Contacts
17
References
18
Distribution List
19
Stop Press
Back Cover
Action: Biological Records Centre (6 copies) Suffolk Biological Records Centre (12)
Information: As per "Suffolk Argus" to members (230, please pass to a colleague) Suffolk Wildlife Trust (20) Suffolk Naturalists Society (6) Norfolk Branch BC (6) Cambs & Essex Branch BC (6)
Photography by Malcolm Farrow & Rob Parker
Blaxhall Parish Council (2) Blaxhall Volunteers (12, c/o T. Peake) R.H. & R. Paul (2) RSPB (6) Forestry Commission (S. Leatherdale) Dr N. Ravenscroft Suffolk Coasts & Heaths Unit (6, to include Connect Fund sponsors)
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The Suffolk Argus
Special Edition - Summer 2008
References [1] Suffolk Local BAP & SAP for Silver-studded Blue. Suffolk County Council. [2] Translocation Proposal for the Silver-studded Blue Butterfly dated 30 Jan 07. [3] Natural England consents: Minsmere-Walberswick/Cor, Sutton & Hollesley Heaths/Cor, Blaxhall Heath/Cor, all dated 13 June 2007. [4] Suffolk Local BAP & HAP for Lowland Heathland. Suffolk County Council.
Studies & Reports Anon. UK Biodiversity Action Plan: Species Action Plan for Plebejus argus. Harris, J. 2006. Translocation of the Silver-studded Blue (Plebejus argus) to Cawston Heath – July 2006. Joy, J. 2000. Butterfly Conservation Regional Action Plan for Anglia Mendel, H. & Parsons, E. 1987. Observations on the Life-history of the Silverstudded Blue, Plebejus argus L. Trans Suffolk Nat. Soc. 23. Parker, R. Annual Butterfly Reports, 2003 to 2006. Suffolk Natural History Vols. 39 to 42. Ravenscroft N. O. M. 1996. A Recovery Plan for the Silver-studded Blue Butterfly on the Sandlings, Suffolk. Report to the Suffolk Wildlife Trust Sandlings Team. Ravenscroft N. O. M., 2003. Status and Management of the Silver-studded Blue Butterfly on the Sandlings, Suffolk 2003. Report to SWT. Stewart, R. G., Annual Butterfly Reports 1995 to 2006. Suffolk Natural History Vols. 32 to 38.
Report on re-establishment attempt for Silver-studded Blue (Plebejus argus) at Blaxhall Common, Suffolk This booklet has been produced to present the formal report on the translocation of wild Silver-studded Blue butterflies (Plebejus argus) to the designated Site of Special Scientific Interest at Blaxhall Common. The report is presented in two forms, firstly, that required for the Biological Records Centre, as stipulated in the 1986 JCCBI code, and secondly, a more detailed chronological account with photographs and maps. The latter may assist other groups undertaking translocations or re-introductions of this species. This booklet has been produced as a special edition of “Suffolk Argus”, and is being given a wide distribution amongst the members of the Suffolk Branch of Butterfly Conservation and the other conservation groups and volunteers who contributed to this project. R. Parker Conservation Officer (Butterflies) Suffolk Branch of Butterflly Conservation
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The Suffolk Argus
Special Edition - Summer 2008
Suffolk Branch Contacts
Proforma Report President
JOINT COMMITTEE FOR THE CONSERVATION OF BRITISH INSECTS
RECORD OF INSECT ESTABLISHMENT SPECIES
Plebejus argus
ORDER
Lepidoptera
DATE OF LAST RECORD
DD/MM
DATE OF ESTABLISHMENT
YYYY
DD/MM
YYYY
1920
3-Jul
2007
REASONS FOR ESTABLISHMENT
Species Conservation Notes: as per Species Action Plan Last record date
Translocation in 2 stages
disregards 1997 sightings attributed to a clandestine release.
30 on 18 Jun, 30 on 3 Jul.
NAME OF RECEIVING SITE BLAXHALL COMMON Grid Reference TM 378568 COUNTY SUFFOLK CONSERVATION STATUS Site of Special Scientific Interest
SITE OWNER Blaxhall Parish Council c/o Pack Gate Cottage Mill Common, Blaxhall Suffolk, IP12 2ED SPECIFIC MANAGEMENT OF RECEIVING SITE
By SWT as Sandlings Heath SSSI. Scrub clearance, bracken control.
Heather areas foraged periodically. DETAILS OF INTRODUCED STOCK LIFESTAGE AND NUMBERS INTRODUCED Ova Larva Pupa Adult male Adult female Total nil nil nil 10 20 30 nil nil nil 10 20 30 60 ORIGIN (18 Jun) Grid Ref ORIGIN (3 Jul) Site Name: Minsmere Sawmills TM452692 Site Name: Lower Hollesley Common County: Suffolk County: Suffolk Owner: RSPB Owner: R. H. & R. Paul Address: Minsmere Nature Reserve, Westleton Address: Broxtead Estate Office Saxmundham, Suffolk IP17 3BY
Owners, Stock Sites Owner Receiving Site Natural England Butterfly Conservation Suffolk Wildlife Trust
Howard Mendel c/o The Natural History Museum Cromwell Road, London SW7 5BD 0207 938 8782
Peter Maddison Barnmead, Fishpond Rd Waldringfield, Woodbridge IP12 4QX
Chairman
01473 736607
Mike Dean Coach House, Ixworth Bury St Edmunds IP31 2HL 01359 230292
Conservation Officer (Butterflies) and County Recorder Rob Parker 66 Cornfield Road Bury St Edmunds IP33 3BN 01284 705476
Membership Secretary Dates 18-Jun-07 3-Jul-07 Grid Ref TM 342465
Susan Sidle Five Gables, The Ling Wortham, Diss, Norfolk IP22 1ST
Conservation Officer (Moths) and Branch Secretary Tony Prichard 3 Powling Road, Ipswich IP3 9JR 01473 270047
Tel 01379 643665
Treasurer
Sutton, Woodbridge, Suffolk IP12 3HL
SPECIFIC PARASITES INTRODUCED Nil. CONSULTATION
Programme Secretary and Newsletter Editor
DD/MM
YYYY
NAME OF PERSON CARRYING OUT ESTABLISHMENT
13-Nov 13-Nov 8-Nov 24-Nov 1-Nov
2006 2006 2006 2006 2006
Mr R. PARKER 66, Cornfield Rd Bury St Edmunds Suffolk, IP33 3BN
Jim Foster Lugano, The Street, Stonham Aspal Stowmarket IP14 6AH 01449 711484
Regional Officer, Eastern England Sharon Hearle c/o Busy Bee, 21 High Street Newmarket CB8 8LX 01638 731648
NAME OF FORM COMPILER
Mr R. PARKER as above DATE:
17-Jan-08
Committee Member
JOINT COMMITTEE FOR THE CONSERVATION OF BRITISH INSECTS
Stella Wolfe
RECORD OF INSECT ESTABLISHMENT (2) SPECIES
Plebejus argus
NAME OF RECEIVING SITE BLAXHALL COMMON Grid Reference TM 378568 COUNTY SUFFOLK
SUBSEQUENT HISTORY Single-species transect established for future population monitoring. 2007 flight period finished by 26 Jul (to be expected).
4
The Suffolk Argus is published by the Suffolk Branch of Butterfly Conservation. © 2008 All rights reserved. For more information, see: www.suffolkbutterflies.org.uk Butterfly Conservation is limited by guarantee. Registered Office: Manor Yard, East Lulworth, Wareham, Dorset, BH20 5QP Tel: 01929 400209 Registered Charity No 254937.
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Special Edition - Summer 2008
The Suffolk Argus
The butterflies are released into the care of Terry Peake at Blaxhall Common.
Blaxhall Common in June 2007, showing a good proportion of bell heather.
The last butterfly of the first batch is released at Blaxhall Common, with David Mason looking on.
Sharon Hearle transfers Silver-studded Blues to their "tent" at RSPB Minsmere.
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The Suffolk Argus
Special Edition - Summer 2008
Report on 2007 Translocation of Silver-studded Blue, Plebejus argus, to Blaxhall Common, Suffolk. translocations, one from each of Lower Hollesley and the Sawmills colony near Minsmere, one to be conducted at the peak flight period, and the other two weeks later. The intention was to move as many mating pairs as possible, with the balance made up to 30 adult butterflies from each donor site. See [2] for full detail.
This report covers the translocation of Silver-studded Blue to Blaxhall Common SSSI. The activity was organised jointly by Butterfly Conservation (Suffolk Branch) and the Suffolk Wildlife Trust in pursuance of the objectives of the Suffolk Local Biodiversity Action Plan [1]. The active phase was completed on 8 July 2007.
Codes & Guidance Care has been taken to plan the translocations in accordance with the best advice available, and particular attention has been paid to the following codes and guidance. Organisation
date
Full Title
Joint Committee for the Conservation of British Insects.
1986 m
Insect Re-establishment - a code of conservation practice.
English Nature. m m m
1995 m m m
Guidance Notes for Invertebrate Translocations and Introductions. (from the Species Conservation Handbook)
Butterfly Conservation.
2001
Lepidoptera Restoration, revised.
Timing.
Approvals.
Following an unusually hot April, the 2007season began early, and the first Silver-studded Blues made their appearance in Suffolk on 4th June, two days earlier than ever previously recorded. In view of this, the first translocation was conducted on 18 June.
The necessary consents were obtained in advance from Natural England, Butterfly Conservation Head Office, landowners at the donor sites - (R.H & R. Paul for Sutton and Hollesley Heaths SSSI (Lower Hollesley Common), and RSPB for MinsmereWalberswick Heaths and Marshes SSSI (Sawmills site), and at the receiving site, Blaxhall Parish Council. The detailed proposal was submitted to Natural England [2] on 30 Jan 07. A final check for the presence of Lasius ants was successfully conducted on 9th May, and letters of consent [3] were issued on 13th June.
First Translocation – 18 Jun 07. A SWT/BC volunteer team of 5 entered the Sawmills site at 11:30 with the weather as forecast: 17C and overcast with a light breeze. Initially, the numbers of butterflies were low, particularly females, but by 12:30 the day was warmer, with a few sunny intervals, and we had little difficulty finding roosting Silver-studded Blues and potting them. Shortage of sun
The Plan. The proposal specified two separate
6
The butterflies are released into the care of Terry Peake at Blaxhall Common. 15
The Suffolk Argus
Special Edition - Summer 2008
Targets for Success A single-species transect has been set up at Blaxhall Common, with a route aimed at detecting any extension to the flight area, as well as making a weekly count. See map on p.10/11. In this way, a fair year-on year comparison will be possible for the new colony. In addition, the existing annual count at all monitored sites will continue, and this will allow any impact at the donor sites to be detected. Targets used to judge success have been set: a. At both donor sites: 2008. A count of at least 90% of the 2006 figure, moderated by any fluctuation noted generally at other Sandlings sites. 2009. A count of 95% of the 2006 figure, moderated as above. 2010 to 2013. Recovery to 100% of 2006 figure. 2014 to 2018. Stable population maintained, subject to seasonal fluctuations & site condition variability. b. At Blaxhall Common: 2008. Some Silver-studded Blues of both sexes detected and apparently breeding on site. Transect walk established. 2009 to 2013. Transect results show population established and increasing within core area. 2014 to 2018. Transect detects expansion of flight area to furthest extent of heather cover.
A grant from the Connect Fund has supported the translocation project expenses, including the production and distribution of this report in its newsletter format. We are grateful to Suffolk Secrets for their generous support through the Suffolk Coast and Heaths Unit.
meant that there was limited flight activity, and we saw no pairings, so we concentrated on collecting females. Their condition was variable; some were very fresh, whilst others had evidently been on the wing for some days, so the chances are good that they had already mated. The proportion of partly blue females (rather like the named aberration var. masseyi) seemed higher than normal, but perhaps this was noted simply because we were handling and inspecting them, rather than just counting them. The 2007 flight season was running early; there were almost as many as would be normal at the peak of the season.
travellers at TM3781 5692. The remaining 3m & 5f were released. Behaviour on release was encouraging. Although a few drifted off in the westerly breeze, most remained feeding on the Erica very close to the release sites, which are separated by about 100m. Each is close to a recently foraged area with pioneer growth already visible, and ant activity in evidence. Second Translocation - 3 Jul 07. The pre-planned translocation from Lower Hollesley was executed on 3 July in bright weather during a generally showery week. All 30 butterflies were taken from Lower Hollesley "A", where they were sufficiently abundant that there was no need to visit the "B" colony. One mating pair was found and moved in cop. The balance comprised 19 females in variable condition and 9 fresh males, making another batch of 10m & 20f in total. These were released at Blaxhall Common from 12:00 to 12:30; using the same 3 release points as the first batch 15 days previously. Most remained in the immediate vicinity of the release points, just resting on heather. After the releases, a single male was encountered in the north of the common, presumably a survivor from the 18 June release.
The butterflies were collected in clear plastic pots and transferred to a fine mesh enclosed cage, which gave them an opportunity to pair, but none of them did so. In all 20 females were taken, and 10 males. Some rejection behaviour was noted, suggesting earlier pairing had occurred. Fortunately the threatened showers avoided Minsmere and Blaxhall, where we arrived and made the releases at 14:30 at three pre-planned spots: 1. The open area of short Erica that was once an informal car park at TM3791 5675. Here we released 3 males and 7 females. 2. The area of the ancient mound at TM3789 5689. 4 males & 8 females were released. 3. The open area formerly used by
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The Suffolk Argus
Special Edition - Summer 2008
The Team
The Role of Ants
The translocation was organised jointly by the Suffolk Branch of Butterfly Conservation and the Suffolk Wildlife Trust.
H. Taylor R. Turner
The team involved in this project includes a few permanent members of staff of Butterfly Conservation, the Suffolk Wildlife Trust and the RSPB, but the majority of the team were volunteers from those organisations and the Suffolk Naturalists’ Society. Although the actual translocation was completed in 2007, the ongoing monitoring and site maintenance will require an enthusiastic volunteer team for years to come. The existing local SWT group at Blaxhall Common will continue doing the site management, and their leader, Terry Peake, will also organise the new transect walk. Those who have participated to date include: Blaxhall SWT Volunteers T. Peake (Warden) A. Chapman J. Day S. Exton J. Forbes M. Forbes A. Freer S. Freer G. Haywood-Smith L. Merrion F. Pynn A.Salisbury
8
Butterfly Conservation M. Austin M.Farrow J. Foster R. Foster A. Johnson B. Johnson S. Keeley R. Parker S. Peck G. Proctor S. Wolfe SNS Mr. Blacker Snr N. Blacker N. Cuming N. Mahler Other SWT N. Mason (Hollesley Warden) K. Thacker S. Thacker Staff Participants R. Harvey (RSPB), M. Kemp (RSPB), D. Kidney (Natural England), D. Mason (SWT), S. Hearle (Butterfly Conservation)
The Silver-studded Blue (Plebejus argus) depends on ants for the satisfactory completion of its life-cycle. This is described as a myrmecophilic relationship. Eggs are deposited close to the ground in areas frequented by ants, sometimes on plants that the larvae can eat, but also on bracken and under stones, where they lie until the following winter. The main larval host plants are heather, bird’s-foot trefoil and gorse, but only tender “pioneer” shoots are eaten. The young larvae are found and tended by ants of a few species within the genus Lasius. Lasius psammophilus (formerly referred to as L. alienus), nests all over the common, but particularly where vegetation is sparse and sunlight reaches the ground. L. niger is also present, but in lesser numbers. The ants are attracted to a sweet substance, which the larva secretes from a honey gland on its back. The presence of the ants protects the larvae from predators, notably parasitic wasps, and their reward is the honey. When the larvae are ready to pupate, they are accompanied underground by the ants, usually into an ants nest. They do not eat the ant grubs in the way of the Large Blue, but benefit from continued protection until they are ready to hatch. Their chances of surviving a fire on the heath are much improved whilst below ground.
The adult butterfly emerges from its chrysalis in late June, and crawls out of the nest in the company of a cluster of ants, giving it continued protection during the period of vulnerability whilst it dries its wings for flight.
Larva of P. argus attracts black ants of Genus Lasius
13
The Suffolk Argus
Special Edition - Summer 2008
Site Management.
Publicity.
Early Monitoring.
catches the wind.
Already a SSSI, the site is managed in pursuit of the Lowland Heathland habitat action plan [4]. The common has been brought up to a suitable condition for Silver-studded Blue by the endeavours of SWT staff and a team of local volunteers. Heather cutting, silver birch removal, bracken control and the creation of bare areas have all been necessary. This work has been done largely by local volunteers, acting through SWT, and with the financial support of SITA (landfill grant) and Natural England. A continuing commitment to heathland management is essential to maintaining the right habitat for the butterfly.
Press releases resulted in two articles appearing in the Eastern Daily Press and one broadcast on BBC Radio Suffolk. These undoubtedly had an educational effect on the public, as well as drawing attention to the good work being done by SWT and Butterfly Conservation.
During a walk round the intended transect route 10 days after the first translocation, David Mason (SWT) found one male and one female on Section 4, northwest of the most northerly release site. The follow-up visit on 8 July was a success, and also found that area occupied. A team of 19 BC/SNS volunteers walked the intended transect route on a broad front, and found as follows (5 days after the second release):
The overall impression was that the butterflies have moved a little northwest, but are settled into the habitat. It is encouraging to have found at least 14, five showery days after the release. Doubtless others remained on unvisited parts of the common. We must hope that plenty of eggs have been laid.
Lessons Learned. It was not possible to collect mating pairs on the days that the translocations were planned, and this could mean that fewer eggs were laid than we would have wished. Partly, this was the result of setting a date in advance and finding that the weather, whilst meeting our minimum criteria, fell short of perfect mating conditions. Better results might have been achieved with a more flexible approach to timing.
Volunteers. This project has harnessed the endeavours of the existing team of Blaxhall Common volunteers, led by Terry Peake, and of active members of the Suffolk Naturalists’ Society, Butterfly Conservation and the Suffolk Wildlife Trust. At least 33 individuals contributed to work during the first year.
Enough Eggs? Conceptually, our two batches of 20 females might have laid 100 eggs each, leaving a total of 4000 ova to overwinter. Allowing for 90% predation in the early stages, 400 adults might emerge in 2008, 200 being females; a five-fold increase over the number released in 2007. That would be a firm foundation for the future, but such projections can be over-optimistic!
Financial Support. A grant from the Connect Fund, administered by the Suffolk Coast and Heaths Unit, supported project expenditure. This included volunteer expenses, an interpretation board, and the production of this report.
12
A few informal visits produced sightings in the following weeks, but by 26th July, unsurprisingly, there were none left on the wing.
Release Point 1. One male was found in the immediate vicinity, and a second flew through later.
Future Monitoring. A single-species transect has been established, and volunteer walkers found. They have walked it for the remainder of this season for familiarisation. It begins further south than the first release point, and stretches further northwest than any of the 3 release areas. Next season's results will show whether the translocation has been an initial success, and future years will determine whether the colony becomes properly established and extends. Under the relevant guidelines for Introductions and Translocations [see Table on page 15], we are encouraged to continue monitoring the site for 10 years.
North-western end of transect. Two males and two females were found roosting in medium height heather along Section 4 of the transect, close to the stump, which is 100m west of Release Point 2. Release Point 2. At least 8 (approx 4f & 4m) were found resting within 20m of Release Point 2, which is the patch of short heather formerly used by travellers. As we moved into the area in the sun, they began to fly, so we avoided double counting, but there were probably more than just 8. Most were roosting on Calluna rather than the Erica which was in flower, and always nearby. Release Point 3. The hillocks of the tumuli looked suitable to the human eye, but had been abandoned by the butterflies, possibly because it is the highest point of the common, and
9
The Suffolk Argus
Special Edition - Summer 2008
10
11
The Suffolk Argus
Special Edition - Summer 2008
10
11
The Suffolk Argus
Special Edition - Summer 2008
Site Management.
Publicity.
Early Monitoring.
catches the wind.
Already a SSSI, the site is managed in pursuit of the Lowland Heathland habitat action plan [4]. The common has been brought up to a suitable condition for Silver-studded Blue by the endeavours of SWT staff and a team of local volunteers. Heather cutting, silver birch removal, bracken control and the creation of bare areas have all been necessary. This work has been done largely by local volunteers, acting through SWT, and with the financial support of SITA (landfill grant) and Natural England. A continuing commitment to heathland management is essential to maintaining the right habitat for the butterfly.
Press releases resulted in two articles appearing in the Eastern Daily Press and one broadcast on BBC Radio Suffolk. These undoubtedly had an educational effect on the public, as well as drawing attention to the good work being done by SWT and Butterfly Conservation.
During a walk round the intended transect route 10 days after the first translocation, David Mason (SWT) found one male and one female on Section 4, northwest of the most northerly release site. The follow-up visit on 8 July was a success, and also found that area occupied. A team of 19 BC/SNS volunteers walked the intended transect route on a broad front, and found as follows (5 days after the second release):
The overall impression was that the butterflies have moved a little northwest, but are settled into the habitat. It is encouraging to have found at least 14, five showery days after the release. Doubtless others remained on unvisited parts of the common. We must hope that plenty of eggs have been laid.
Lessons Learned. It was not possible to collect mating pairs on the days that the translocations were planned, and this could mean that fewer eggs were laid than we would have wished. Partly, this was the result of setting a date in advance and finding that the weather, whilst meeting our minimum criteria, fell short of perfect mating conditions. Better results might have been achieved with a more flexible approach to timing.
Volunteers. This project has harnessed the endeavours of the existing team of Blaxhall Common volunteers, led by Terry Peake, and of active members of the Suffolk Naturalists’ Society, Butterfly Conservation and the Suffolk Wildlife Trust. At least 33 individuals contributed to work during the first year.
Enough Eggs? Conceptually, our two batches of 20 females might have laid 100 eggs each, leaving a total of 4000 ova to overwinter. Allowing for 90% predation in the early stages, 400 adults might emerge in 2008, 200 being females; a five-fold increase over the number released in 2007. That would be a firm foundation for the future, but such projections can be over-optimistic!
Financial Support. A grant from the Connect Fund, administered by the Suffolk Coast and Heaths Unit, supported project expenditure. This included volunteer expenses, an interpretation board, and the production of this report.
12
A few informal visits produced sightings in the following weeks, but by 26th July, unsurprisingly, there were none left on the wing.
Release Point 1. One male was found in the immediate vicinity, and a second flew through later.
Future Monitoring. A single-species transect has been established, and volunteer walkers found. They have walked it for the remainder of this season for familiarisation. It begins further south than the first release point, and stretches further northwest than any of the 3 release areas. Next season's results will show whether the translocation has been an initial success, and future years will determine whether the colony becomes properly established and extends. Under the relevant guidelines for Introductions and Translocations [see Table on page 15], we are encouraged to continue monitoring the site for 10 years.
North-western end of transect. Two males and two females were found roosting in medium height heather along Section 4 of the transect, close to the stump, which is 100m west of Release Point 2. Release Point 2. At least 8 (approx 4f & 4m) were found resting within 20m of Release Point 2, which is the patch of short heather formerly used by travellers. As we moved into the area in the sun, they began to fly, so we avoided double counting, but there were probably more than just 8. Most were roosting on Calluna rather than the Erica which was in flower, and always nearby. Release Point 3. The hillocks of the tumuli looked suitable to the human eye, but had been abandoned by the butterflies, possibly because it is the highest point of the common, and
9
The Suffolk Argus
Special Edition - Summer 2008
The Team
The Role of Ants
The translocation was organised jointly by the Suffolk Branch of Butterfly Conservation and the Suffolk Wildlife Trust.
H. Taylor R. Turner
The team involved in this project includes a few permanent members of staff of Butterfly Conservation, the Suffolk Wildlife Trust and the RSPB, but the majority of the team were volunteers from those organisations and the Suffolk Naturalists’ Society. Although the actual translocation was completed in 2007, the ongoing monitoring and site maintenance will require an enthusiastic volunteer team for years to come. The existing local SWT group at Blaxhall Common will continue doing the site management, and their leader, Terry Peake, will also organise the new transect walk. Those who have participated to date include: Blaxhall SWT Volunteers T. Peake (Warden) A. Chapman J. Day S. Exton J. Forbes M. Forbes A. Freer S. Freer G. Haywood-Smith L. Merrion F. Pynn A.Salisbury
8
Butterfly Conservation M. Austin M.Farrow J. Foster R. Foster A. Johnson B. Johnson S. Keeley R. Parker S. Peck G. Proctor S. Wolfe SNS Mr. Blacker Snr N. Blacker N. Cuming N. Mahler Other SWT N. Mason (Hollesley Warden) K. Thacker S. Thacker Staff Participants R. Harvey (RSPB), M. Kemp (RSPB), D. Kidney (Natural England), D. Mason (SWT), S. Hearle (Butterfly Conservation)
The Silver-studded Blue (Plebejus argus) depends on ants for the satisfactory completion of its life-cycle. This is described as a myrmecophilic relationship. Eggs are deposited close to the ground in areas frequented by ants, sometimes on plants that the larvae can eat, but also on bracken and under stones, where they lie until the following winter. The main larval host plants are heather, bird’s-foot trefoil and gorse, but only tender “pioneer” shoots are eaten. The young larvae are found and tended by ants of a few species within the genus Lasius. Lasius psammophilus (formerly referred to as L. alienus), nests all over the common, but particularly where vegetation is sparse and sunlight reaches the ground. L. niger is also present, but in lesser numbers. The ants are attracted to a sweet substance, which the larva secretes from a honey gland on its back. The presence of the ants protects the larvae from predators, notably parasitic wasps, and their reward is the honey. When the larvae are ready to pupate, they are accompanied underground by the ants, usually into an ants nest. They do not eat the ant grubs in the way of the Large Blue, but benefit from continued protection until they are ready to hatch. Their chances of surviving a fire on the heath are much improved whilst below ground.
The adult butterfly emerges from its chrysalis in late June, and crawls out of the nest in the company of a cluster of ants, giving it continued protection during the period of vulnerability whilst it dries its wings for flight.
Larva of P. argus attracts black ants of Genus Lasius
13
The Suffolk Argus
Special Edition - Summer 2008
Targets for Success A single-species transect has been set up at Blaxhall Common, with a route aimed at detecting any extension to the flight area, as well as making a weekly count. See map on p.10/11. In this way, a fair year-on year comparison will be possible for the new colony. In addition, the existing annual count at all monitored sites will continue, and this will allow any impact at the donor sites to be detected. Targets used to judge success have been set: a. At both donor sites: 2008. A count of at least 90% of the 2006 figure, moderated by any fluctuation noted generally at other Sandlings sites. 2009. A count of 95% of the 2006 figure, moderated as above. 2010 to 2013. Recovery to 100% of 2006 figure. 2014 to 2018. Stable population maintained, subject to seasonal fluctuations & site condition variability. b. At Blaxhall Common: 2008. Some Silver-studded Blues of both sexes detected and apparently breeding on site. Transect walk established. 2009 to 2013. Transect results show population established and increasing within core area. 2014 to 2018. Transect detects expansion of flight area to furthest extent of heather cover.
A grant from the Connect Fund has supported the translocation project expenses, including the production and distribution of this report in its newsletter format. We are grateful to Suffolk Secrets for their generous support through the Suffolk Coast and Heaths Unit.
meant that there was limited flight activity, and we saw no pairings, so we concentrated on collecting females. Their condition was variable; some were very fresh, whilst others had evidently been on the wing for some days, so the chances are good that they had already mated. The proportion of partly blue females (rather like the named aberration var. masseyi) seemed higher than normal, but perhaps this was noted simply because we were handling and inspecting them, rather than just counting them. The 2007 flight season was running early; there were almost as many as would be normal at the peak of the season.
travellers at TM3781 5692. The remaining 3m & 5f were released. Behaviour on release was encouraging. Although a few drifted off in the westerly breeze, most remained feeding on the Erica very close to the release sites, which are separated by about 100m. Each is close to a recently foraged area with pioneer growth already visible, and ant activity in evidence. Second Translocation - 3 Jul 07. The pre-planned translocation from Lower Hollesley was executed on 3 July in bright weather during a generally showery week. All 30 butterflies were taken from Lower Hollesley "A", where they were sufficiently abundant that there was no need to visit the "B" colony. One mating pair was found and moved in cop. The balance comprised 19 females in variable condition and 9 fresh males, making another batch of 10m & 20f in total. These were released at Blaxhall Common from 12:00 to 12:30; using the same 3 release points as the first batch 15 days previously. Most remained in the immediate vicinity of the release points, just resting on heather. After the releases, a single male was encountered in the north of the common, presumably a survivor from the 18 June release.
The butterflies were collected in clear plastic pots and transferred to a fine mesh enclosed cage, which gave them an opportunity to pair, but none of them did so. In all 20 females were taken, and 10 males. Some rejection behaviour was noted, suggesting earlier pairing had occurred. Fortunately the threatened showers avoided Minsmere and Blaxhall, where we arrived and made the releases at 14:30 at three pre-planned spots: 1. The open area of short Erica that was once an informal car park at TM3791 5675. Here we released 3 males and 7 females. 2. The area of the ancient mound at TM3789 5689. 4 males & 8 females were released. 3. The open area formerly used by
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Report on 2007 Translocation of Silver-studded Blue, Plebejus argus, to Blaxhall Common, Suffolk. translocations, one from each of Lower Hollesley and the Sawmills colony near Minsmere, one to be conducted at the peak flight period, and the other two weeks later. The intention was to move as many mating pairs as possible, with the balance made up to 30 adult butterflies from each donor site. See [2] for full detail.
This report covers the translocation of Silver-studded Blue to Blaxhall Common SSSI. The activity was organised jointly by Butterfly Conservation (Suffolk Branch) and the Suffolk Wildlife Trust in pursuance of the objectives of the Suffolk Local Biodiversity Action Plan [1]. The active phase was completed on 8 July 2007.
Codes & Guidance Care has been taken to plan the translocations in accordance with the best advice available, and particular attention has been paid to the following codes and guidance. Organisation
date
Full Title
Joint Committee for the Conservation of British Insects.
1986 m
Insect Re-establishment - a code of conservation practice.
English Nature. m m m
1995 m m m
Guidance Notes for Invertebrate Translocations and Introductions. (from the Species Conservation Handbook)
Butterfly Conservation.
2001
Lepidoptera Restoration, revised.
Timing.
Approvals.
Following an unusually hot April, the 2007season began early, and the first Silver-studded Blues made their appearance in Suffolk on 4th June, two days earlier than ever previously recorded. In view of this, the first translocation was conducted on 18 June.
The necessary consents were obtained in advance from Natural England, Butterfly Conservation Head Office, landowners at the donor sites - (R.H & R. Paul for Sutton and Hollesley Heaths SSSI (Lower Hollesley Common), and RSPB for MinsmereWalberswick Heaths and Marshes SSSI (Sawmills site), and at the receiving site, Blaxhall Parish Council. The detailed proposal was submitted to Natural England [2] on 30 Jan 07. A final check for the presence of Lasius ants was successfully conducted on 9th May, and letters of consent [3] were issued on 13th June.
First Translocation – 18 Jun 07. A SWT/BC volunteer team of 5 entered the Sawmills site at 11:30 with the weather as forecast: 17C and overcast with a light breeze. Initially, the numbers of butterflies were low, particularly females, but by 12:30 the day was warmer, with a few sunny intervals, and we had little difficulty finding roosting Silver-studded Blues and potting them. Shortage of sun
The Plan. The proposal specified two separate
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The butterflies are released into the care of Terry Peake at Blaxhall Common. 15
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The Suffolk Argus
The butterflies are released into the care of Terry Peake at Blaxhall Common.
Blaxhall Common in June 2007, showing a good proportion of bell heather.
The last butterfly of the first batch is released at Blaxhall Common, with David Mason looking on.
Sharon Hearle transfers Silver-studded Blues to their "tent" at RSPB Minsmere.
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Suffolk Branch Contacts
Proforma Report President
JOINT COMMITTEE FOR THE CONSERVATION OF BRITISH INSECTS
RECORD OF INSECT ESTABLISHMENT SPECIES
Plebejus argus
ORDER
Lepidoptera
DATE OF LAST RECORD
DD/MM
DATE OF ESTABLISHMENT
YYYY
DD/MM
YYYY
1920
3-Jul
2007
REASONS FOR ESTABLISHMENT
Species Conservation Notes: as per Species Action Plan Last record date
Translocation in 2 stages
disregards 1997 sightings attributed to a clandestine release.
30 on 18 Jun, 30 on 3 Jul.
NAME OF RECEIVING SITE BLAXHALL COMMON Grid Reference TM 378568 COUNTY SUFFOLK CONSERVATION STATUS Site of Special Scientific Interest
SITE OWNER Blaxhall Parish Council c/o Pack Gate Cottage Mill Common, Blaxhall Suffolk, IP12 2ED SPECIFIC MANAGEMENT OF RECEIVING SITE
By SWT as Sandlings Heath SSSI. Scrub clearance, bracken control.
Heather areas foraged periodically. DETAILS OF INTRODUCED STOCK LIFESTAGE AND NUMBERS INTRODUCED Ova Larva Pupa Adult male Adult female Total nil nil nil 10 20 30 nil nil nil 10 20 30 60 ORIGIN (18 Jun) Grid Ref ORIGIN (3 Jul) Site Name: Minsmere Sawmills TM452692 Site Name: Lower Hollesley Common County: Suffolk County: Suffolk Owner: RSPB Owner: R. H. & R. Paul Address: Minsmere Nature Reserve, Westleton Address: Broxtead Estate Office Saxmundham, Suffolk IP17 3BY
Owners, Stock Sites Owner Receiving Site Natural England Butterfly Conservation Suffolk Wildlife Trust
Howard Mendel c/o The Natural History Museum Cromwell Road, London SW7 5BD 0207 938 8782
Peter Maddison Barnmead, Fishpond Rd Waldringfield, Woodbridge IP12 4QX
Chairman
01473 736607
Mike Dean Coach House, Ixworth Bury St Edmunds IP31 2HL 01359 230292
Conservation Officer (Butterflies) and County Recorder Rob Parker 66 Cornfield Road Bury St Edmunds IP33 3BN 01284 705476
Membership Secretary Dates 18-Jun-07 3-Jul-07 Grid Ref TM 342465
Susan Sidle Five Gables, The Ling Wortham, Diss, Norfolk IP22 1ST
Conservation Officer (Moths) and Branch Secretary Tony Prichard 3 Powling Road, Ipswich IP3 9JR 01473 270047
Tel 01379 643665
Treasurer
Sutton, Woodbridge, Suffolk IP12 3HL
SPECIFIC PARASITES INTRODUCED Nil. CONSULTATION
Programme Secretary and Newsletter Editor
DD/MM
YYYY
NAME OF PERSON CARRYING OUT ESTABLISHMENT
13-Nov 13-Nov 8-Nov 24-Nov 1-Nov
2006 2006 2006 2006 2006
Mr R. PARKER 66, Cornfield Rd Bury St Edmunds Suffolk, IP33 3BN
Jim Foster Lugano, The Street, Stonham Aspal Stowmarket IP14 6AH 01449 711484
Regional Officer, Eastern England Sharon Hearle c/o Busy Bee, 21 High Street Newmarket CB8 8LX 01638 731648
NAME OF FORM COMPILER
Mr R. PARKER as above DATE:
17-Jan-08
Committee Member
JOINT COMMITTEE FOR THE CONSERVATION OF BRITISH INSECTS
Stella Wolfe
RECORD OF INSECT ESTABLISHMENT (2) SPECIES
Plebejus argus
NAME OF RECEIVING SITE BLAXHALL COMMON Grid Reference TM 378568 COUNTY SUFFOLK
SUBSEQUENT HISTORY Single-species transect established for future population monitoring. 2007 flight period finished by 26 Jul (to be expected).
4
The Suffolk Argus is published by the Suffolk Branch of Butterfly Conservation. © 2008 All rights reserved. For more information, see: www.suffolkbutterflies.org.uk Butterfly Conservation is limited by guarantee. Registered Office: Manor Yard, East Lulworth, Wareham, Dorset, BH20 5QP Tel: 01929 400209 Registered Charity No 254937.
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References [1] Suffolk Local BAP & SAP for Silver-studded Blue. Suffolk County Council. [2] Translocation Proposal for the Silver-studded Blue Butterfly dated 30 Jan 07. [3] Natural England consents: Minsmere-Walberswick/Cor, Sutton & Hollesley Heaths/Cor, Blaxhall Heath/Cor, all dated 13 June 2007. [4] Suffolk Local BAP & HAP for Lowland Heathland. Suffolk County Council.
Studies & Reports Anon. UK Biodiversity Action Plan: Species Action Plan for Plebejus argus. Harris, J. 2006. Translocation of the Silver-studded Blue (Plebejus argus) to Cawston Heath – July 2006. Joy, J. 2000. Butterfly Conservation Regional Action Plan for Anglia Mendel, H. & Parsons, E. 1987. Observations on the Life-history of the Silverstudded Blue, Plebejus argus L. Trans Suffolk Nat. Soc. 23. Parker, R. Annual Butterfly Reports, 2003 to 2006. Suffolk Natural History Vols. 39 to 42. Ravenscroft N. O. M. 1996. A Recovery Plan for the Silver-studded Blue Butterfly on the Sandlings, Suffolk. Report to the Suffolk Wildlife Trust Sandlings Team. Ravenscroft N. O. M., 2003. Status and Management of the Silver-studded Blue Butterfly on the Sandlings, Suffolk 2003. Report to SWT. Stewart, R. G., Annual Butterfly Reports 1995 to 2006. Suffolk Natural History Vols. 32 to 38.
Report on re-establishment attempt for Silver-studded Blue (Plebejus argus) at Blaxhall Common, Suffolk This booklet has been produced to present the formal report on the translocation of wild Silver-studded Blue butterflies (Plebejus argus) to the designated Site of Special Scientific Interest at Blaxhall Common. The report is presented in two forms, firstly, that required for the Biological Records Centre, as stipulated in the 1986 JCCBI code, and secondly, a more detailed chronological account with photographs and maps. The latter may assist other groups undertaking translocations or re-introductions of this species. This booklet has been produced as a special edition of “Suffolk Argus”, and is being given a wide distribution amongst the members of the Suffolk Branch of Butterfly Conservation and the other conservation groups and volunteers who contributed to this project. R. Parker Conservation Officer (Butterflies) Suffolk Branch of Butterflly Conservation
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Contents
Distribution of this report:
Covering letter
3
Record of Re-establishment proforma
4
Report on 2007 Translocation
6-12
Blaxhall Common map
10/11
Natural England (6)
The role of Ants
13
Invertebrate Link (6)
Targets for Success
14
Butterfly Conservation Head Office (6)
Codes & Guidance
15
Suffolk Branch Contacts
17
References
18
Distribution List
19
Stop Press
Back Cover
Action: Biological Records Centre (6 copies) Suffolk Biological Records Centre (12)
Information: As per "Suffolk Argus" to members (230, please pass to a colleague) Suffolk Wildlife Trust (20) Suffolk Naturalists Society (6) Norfolk Branch BC (6) Cambs & Essex Branch BC (6)
Photography by Malcolm Farrow & Rob Parker
Blaxhall Parish Council (2) Blaxhall Volunteers (12, c/o T. Peake) R.H. & R. Paul (2) RSPB (6) Forestry Commission (S. Leatherdale) Dr N. Ravenscroft Suffolk Coasts & Heaths Unit (6, to include Connect Fund sponsors)
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The Suffolk Argus
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Suffolk Argus The
The Newsletter of the Suffolk Branch of Butterfly Conservation
STOP PRESS On 20 June 2008, David Mason (SWT) saw the first Silver-studded Blue that proved that eggs had been laid and that the insects had survived their first winter. Soon after, volunteers walking the transect found numbers rising, and by 4 July, each transect walk was seeing a dozen or more. The peak count was on 13 July, when Terry Peake counted 9 males and 5 females. The butterflies were mostly flying in the immediate vicinity of the release points, but several were also seen in Section 5, near the stump, about 100m west of the former travellers site at the start of Section 7. This number of sightings on a daily basis might reflect a population of about 45 in total, rather less than the 60 released in 2007, but a satisfactory start nonetheless. This initial success was duly reported in the East Anglian Daily Press, and the Times carried a paragraph by Simon Barnes celebrating the remarkable life style of the Silver-studded Blue and its attendant ants. Visits to the donor sites found satisfactory numbers flying at Lower Hollesley Common, and Minsmere Sawmills, so there is no immediate concern that the translocation has had a significant impact on the donor colonies. Re-establishment attempts often produce a successful showing after one year, only to fade out over the next 2 or 3 seasons, so there is no reason to reach for the champagne yet.
Silver-studded Blue by Malcolm Farrow
The translocated Silver-studded Blues settled in their new habitat at Blaxhall Common.
Report on 2007 Translocation of Silver-studded Blue, Plebejus argus to Blaxhall Common, Suffolk Summer 2008
Special Edition