Small Blue Survey
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2012 Small Blue Survey By Iain Cowe February 2013 Contents 1. Introduction 2. Berwickshire Coast North 3. Berwickshire Coast South 4. Berwick Upon Tweed North 5. Berwick Upon Tweed South 6. The East Lothian Question Small Blue Survey Small 7. Inland sites 2013 8. Plans for 2013 9. Summing up 1 INTRODUCTION After last years surveys on the Berwickshire and Northumberland coast, the following are the results of those surveys. A clearer picture of possible and actual Small Blue sites was achieved, but as ever there will always be more to do. Thanks to everyone who took part directly or indirectly, much appreciated. Having more eyes out there looking for Small Blue and the food plant Kidney Vetch is and was a huge help. BERWICKSHIRE COAST NORTH 2 The Berwickshire Coast North section stretches from Bilsdean and Cove in the north too Coldingham in the south. Thus far no Small Blue have been found in the section, and there is little in the way of decent habitat apart from Brander Heugh (illustrated below), StAbbs Head and Coldingham Bay Homeli Knoll. Brander Heugh is a very likely spot, yet its isolation would very probably hinder any chance of colonisation...which is a pity. St Abbs Head is still under recorded and that needs fixing…so little can be said until a proper search is done. Coldingham Bay and Homeli Knoll has seemingly perfect habitat with lots of flowering vetch… Small Blue still possible here, though it has been a good number of years since they were last seen here. Searches were carried out in the north at Cove, Pease Bay, Greenheugh and Ramsheugh yielding little in the way of Kidney Vetch. A few sorties were also made out to Redheugh, Siccar Point and Fast Castle with no positive KV sightings. Brander Heugh A rich flourish of KV spills down a zig zag track way to the shore. Photos by Barry Prater. Greenheugh,Ramsheugh A sparse few patches on the Northern sections either side of the Pease Bay. Photos by Nick Morgan. Coldingham Bay 3 BERWICKSHIRE COAST SOUTH SECTION This is a very rich section from Yellowcraig Head and Linkim Shore in the north to Lamberton in the south. An almost continuous seam of Vetch in varying degrees of density meaning that colonisation from the known sites is very possible. Notable sights are many and from North to south include, Yellowcraig Head, Linkim Shore(south), Linkim Kip to Callercove Point, Killiedraught Bay, Hairy Ness, Fort Point, Eyemouth Bay, Gunsgreen, Ramfauds too Daring, Blaikie Heugh at Hurkers Haven, Breeches too Partanhall. It is at Partanhall where there is quite a gap of a few kilometres before the KV returns at Catcairn, Hilton Bay and Lamberton Beach then fizzling out at Tods Loup. Most of the KV recorded was known from previous botanical surveys, any new records were of very small plant groupings, yet, significant enough to afford the butterfly a stepping stone from one site to another…in theory. Yellowcraig Head Linkim Shore Hairy Ness Kings Gardens Small Blue Site The Kings Gardens site north of Partanhall, Burnmouth was discovered – rediscovered in 2011. The site hugs the shoreline below the steep grass slopes and runs the length of approx. 800 metres from the cottages at Partanhall along a rock and pebble strewn shoreline to Breeches in the north. There is a vast amount of Kidney Vetch on the upper and lower slopes as well as the high tide line. In 2012 a maximum count of 16 Small Blue adults were recorded June 13th. It is quite a complex site to record as most of the terrain is quite simply inaccessible. The tides make surveying quite tricky, and on top of that the site loses the full sun quite early in the day…about 2pm in peak season…so the butterflies tend to be on the wing much earlier in the day. As yet there are no solid historical records for this particular site, though, it seems likely that they have been observed here before as the colony is quite visible. The challenge at this site is expansion…possible colonisation. To the south it looks unlikely as there is little in the way of food plant beyond Partanhall. To the north however there is a very likely spot that lies just 800 metres away at Blaikie Heugh. Can the Small Blue make that leap? Only time will tell. If they did colonise Blaikie…then…a further expansion north to Eyemouth would it seem be quite likely considering the amount of food plant available. In 2012 there were 9 records of Small Blue at Kings Gardens site culminating in a total of 37 individual adult butterflies between 24th May to the 20th of June. No eggs or larvae were recorded. Comparing that with 2011, there were 3 records, culminating in a total of 15 individuals..all visits were made in mid June. Eggs were recorded. EYEMOUTH PENINSULA In June 2010 Barry Prater found 1 adult Small Blue on the cliffside base of Eyemouth Bay. A few days later he returned and saw yet another Small Blue adult. Getting photographs on both occasions it seemed to me at least that these were quite separate individuals. Despite numerous searches since we have been unable to locate any through 2011 and 2012…so…where are they now? Its quite frustrating. As for habitat there is plenty, and after surveying the peninsula in 2012 found very large amounts of Kidney Vetch along the north beach cliffs running up to Fort Point and on sporadically towards Hairy Ness where there is copious amounts of food plant. Yet no butterfly since Barrys sightings. Kidney Vetch is quite constant from this Peninsula north towards Linkim Shore…a distance of roughly one and a half miles following the coast. In theory we could find Small Blue tucked away anywhere from point to point. As I said it is very frustrating not to be able to get to the bottom of this…but…I feel that we will uncover them again soon. All photos by Barry Prater from Eyemouth Bay These are the photos Barry took of the Small Blue individuals on 2 separate occasions, firstly June 16th, then June 22nd. Note the abdomen size of both butterflies. I am convinced enough that they are female first photo, and male 2nd. CATCAIRN SMALL BLUE SITE The Catcairn site situated south of Burnmouth just of the Berwickshire coastal path has been monitored closely since 2007. In 2007 and 2008 only a few butterflies were seen in each season. During 2009 we discovered a good few more, and that can be owed to being a little more adventurous in exploring the steep scree and boulder slope. In 2010 it seemed that the colony were a lot more strung out than we had first thought with quite a few individuals being found quite a way from the main core site. 2011 pretty much confirmed that. In 2012 a new dynamic was introduced to us by the relaxation of sheep grazing to the south of Catcairn. It was very obvious almost immediately that the Small Blue had taken advantage of the cessation in grazing and had spread south quite significantly in numbers utilising all available Kidney Vetch heads. In 2012 I had 15 records of 161 adult butterflies between 16th May through to the 20th June peaking on 26th May with a count of 57. There were 11 larvae found from 26th July to the 16th August. Eggs were not counted, but there were many hatched and unhatched observed from the Northern extent to the southern extent. See map. 2011 comparison reads 11 records of 67 adult Small Blue between May 9th to the 13th of June peaking on May 18th with 19 adults counted. 6 larvae were counted on the 26th July. 18 eggs counted on the 14th May and 14 eggs on a single plant on the 18th of May. From that comparison you may believe that 2012 was a better year than 2011…its not as simple as that. Timing and weather and how often you visit and how long the visit do skew results. The flight period in 2012 was blessed with a window of decent weather unlike 2011. But I feel that the butterfly is very much better than we humans at adapting to certain conditions. And it is easier for us not to bother going out on a less than hopeful day. The most fascinating Small Blue discoveries are to made on the periphery of main core sites, where the very last straggling plants are found. Its there that you can see clear evidence of a struggle to expand. It was on the 20th of June while scouting the cliffs north of Burnmouth when I received a mobile phone call from my brother who was making his way up the coast from Lamberton and came across an adult Small Blue well south of where we were used to seeing them. I immediately tore south to Catcairn and on to Hilton Bay. Just to the north of Lamberton Beach I met my brother whom had lost site of the butterfly…so we waited…and waited. As if by magic the little blue skipped into the air right in front of us..a female, battered and worn, but very capable. Where had she been? Had she been laying eggs? We searched all available heads….nothing. Still the little female flipped and skipped but never committing herself to any particular spot. I pretty much gave up, and slumped by a patch of Kidney Vetch, and as I sat she circled around me, landed on my arm then fluttered down to the very patch of Vetch in front of my eyes and layed a few eggs…astonishing!! On closer inspection I could see that she had been very busy, and for one reason or another this was her chosen spot.