Worcs Brown Hairstreak Update

Well……what an eventful and exciting last few weeks it’s been in the world of the West Midlands Brown Hairstreak!
 The last six months had continued the fairly quiet trend that we had been experiencing since Summer 2015 with adult sightings in Grafton Wood, in 2016, well down on that previous summer. Once this winter’s egg searches then got underway in November, the similar theme continued. Counts at most sites that are monitored every year, were either down or about the same as the previous winter (which was, in itself, a disappointing one). Some sites bucked the trend though such as the National Grid site at Feckenham, which had the best count we’ve ever recorded there, responding to the great management work done by the Worcs Wildlife Trust and National Grid. Plus a long stretch of footpath hedgerow near Bishampton that we’re now using for the new BC Head Office monitoring methodology and where eggs were only found for the first time, a few years ago. Large numbers of eggs were found here this winter, easily surpassing last years’ total and seemingly indicating the build-up of a colony right at the southern edge of the known distribution of the butterfly in Worcs.
Events really started to take off though just before Christmas, with the discovery of what were the most southerly eggs ever found for this current-day Worcs population. These eggs were actually in an already recorded 1Km grid square but later that same day, after moving on to a nearby (previously unrecorded) square and searching there, Jenny Tonry discovered an egg on the northern outskirts of the village of Pinvin, in square SO9549.
A few weeks later, one of our regular Thursday searches had to be cancelled because of a bad weather forecast. Undeterred, two of us then went out searching (independently) the following day, in better weather, with the result that three more previously unrecorded squares were ticked off the list. These three squares were the ones flanking Tibberton village (SO9056/57/58) and were significant in that they’ve all been searched many times before in previous winters, to no avail. These squares were also out near the extreme western edge of the butterfly’s Worcs distribution. So again, these egg records provide compelling evidence of distribution expansion of the butterfly.
It was becoming increasingly clear, from all these ‘new square records’, that the Brown Hairstreak had experienced a flight season characterized by ‘dispersal’ and it was therefore going to be worth putting in a bit of extra effort to try and find other new square territories.
Cue a couple of weeks ago and the discovery of another new square record in yet another location that had been unsuccessfully searched in many previous winters. This one being on Pumphouse Lane, close to Redditch, in SP0166, and these discoveries marked the most northerly eggs so far found. This was then followed, just a week ago, by the discovery of an egg over the border in Warks, east of Astwood Bank plus  egg records in another new ‘Redditch’ square: SP0364 at Hunt End.
We had therefore, in just a single winter, recorded the most northerly and southerly eggs in the distribution, whilst also finding them out very close to both the western and eastern extremes!
With all this ‘edge of distribution’ exploration going on it might seem like there wouldn’t have been much time left to devote to our core area searches at Grafton Wood however, sandwiched in between all these new range discoveries, have been some incredible recent finds within the wood itself. Following a rather abortive attempt at searching some excellent areas of Blackthorn coppice and re-growth, in a much hampered heavy hoar frost search a few weeks previously, we decided to return to carry out a more systematic and painstaking search of some key areas within the wood. The result of these searches was that the in-wood total number of eggs found this winter at Grafton was a staggering 555. One particularly favourable ride corner revealing 186 eggs!

These searches within Grafton Wood itself have only been carried out over the last three winters, and are done to provide a monitoring and planning tool to aid the huge amount of excellent management work that has taken place within Grafton over the last few years to open up the wood and cut down old blackthorn thickets. The egg totals have proved beyond all doubt, how fantastically well the butterfly has responded to all this management work.

This brings the news of an exciting Brown Hairstreak season, right up-to-date although, at the time of writing, there’s still a few more weeks left for egg searching. So who knows what we may yet turn up, before the Blackthorn comes into flower and the 2017 egg searching season draws to a close?

Numbers down - maybe

It has been an interesting year for Brown Hairstreaks in Worcs with adult sightings generally down.  In contrast to 2015, we have had very few reports of nectaring individuals even at favoured spots like the hemp agrimony along the rides at Grafton Wood.  We presume honeydew in the canopy was more plentiful this year than last which may explain the difference.  The real test, of course, of a Brown Hairstreak season is not the number of adults seen but the number of eggs laid.  Our band of Thursday Streakers are yet to venture out with our first foray of the season not planned until 1st December when we shall be descending on Trench Wood near Droitwich.  The real test, however, starts the following Saturday when we commence our annual egg count at Grafton Wood.  This will be our 26th year of counting using the same methodology!  You can find out more about the Brown Hairstreak and indeed other butterflies found around the West Midlands in the new 'Butterflies of the West Midlands' book published earlier this year.  Copies can be ordered from the publishers at www.naturebureau.co.uk/bookshop or at events organised by West Midlands Butterfly Conservation.  For further information about planned egg counts over the winter contact simonjprimrose@aol.com

Egg laying at Grafton - maybe!!

There seem to be far fewer sightings this year, than normal, at this early stage. I'm meeting a lot of people, who tell me that they have seen nothing and, on my visits to Gratin Wood, I've noticed far fewer individuals in flight, than normal. But they are around and, today was my best day of the flight season, so far. I saw four individuals: one flying over the old pond into oaks behind; one flying into the wood from the orchard and two females low down on the narrow path to the west of the old pond.
I think, but I'm not sure, that both of the females were ovipositing. They were crawling along young blackthorn shoots, fluttering low down and basking briefly, but I did not actually see egg-laying or find any eggs.



Egg laying at Grafton Wood (thanks to clearance work)

I was very impressed with the results of the shrub clearance near the old pond area. I saw 7 Brown Hairstreaks, today, all either in the old pond area or along the path to the west of the pond. Two of the females were definitely egg laying, however, in the area cleared either last year or the year before, opposite the pond. All the low flying, egg laying females were in this cleared area.

I think I have been missing a lot of sightings by looking around the area of blackthorn next to the pond, when most of the action is opposite the pond in the cleared area on younger blackthorn plants. The female below disappeared low in the blackthorn and I found two eggs, afterwards.


Most of my sightings were between 12.30 and 14.00pm. It was very windy, but they were active during the short spells of sunshine. I photographed four different females on the day. All in all, a very good day. I did notice that there was a lot of trampling in the cleared area. There are a couple of small "paths" through this area so please try to avoid trampling on the blackthorn saplings. Many thanks.




Early days at Grafton Wood

I read on the Grafton Wood blog that the first Brown Hairstreaks (including females) were seen on August 4th. I arrived last Sunday on a warm, sunny but windy day, feeling very hopeful of early season sightings. I walked the main rides for 3 hours, seeing a particularly strong showing of Gatekeeper, Brimstone and Silver Washed Fritillary. I was surprised that, although I saw 5 Purple Hairstreak (even on the ground), I did not see a single Brown Hairstreak in flight, at all, including around the pond area. My only observations were of two females, low in blackthorn, on the west side of the wood, either basking or nectaring on bramble.
Fortunately, one of the females was very photogenic and posed in virtually all the positions I wanted :-) for two minutes; then she was gone. There is something very special about our rarer woodland species. They spend most of their brief lives high in the canopy, rarely, if ever, descending so that we can fully appreciate their beauty. It is the fruitless hours or days that we spend travelling to, and searching these sites in vain, that makes these brief glimpses so very rewarding.

Any sightings yet

Anybody seen one of these yet. As the Purple Emperor season winds down, attention turns, hopefully, to Brown Hairstreak. I noticed on the Purple Empire that Brown Hairstreak were flying at Knepp, last week. As it is a long drive to my nearest site (Grafton Wood), I wondered whether they were out anywhere else yet. Many thanks.

Annual Transect Egg Count at West Williamston, Pembrokeshire

West Williamston’s annual egg count this year was carried out by 15 enthusiastic volunteers on a damp, grey Pembrokeshire day.  Travelling from all over south Wales.  The team also welcomed several new ‘hairstreakers’. 

The total number of eggs found was surprisingly high compared to reports of lower counts from other areas.  Blackthorn management has continued to be carried out on a rota basis by Nathan Walton, WTSWW officer and his volunteers, and it is worth noting that the areas where eggs laid were most concentrated correlates directly to the areas where most males were seen during August and September.

Aerial GPS locations of 2015 Brown Hairstreak eggs found along the foreshore transect (and beyond) with thanks to Stephen and Anne Coker

West Williamston SSSI Annual Brown Hairstreak Egg Count 
Sunday December 6th 2015. 
Area
No
Volunteers
Blkthorn status   previous year
Blackthorn management
000 - 025
37
 Steven,  Anne,  Sarah & Gerry
v good

025 - 050
91
      “         “          “            “
v good

B Glade
56
      “         “        
V good

B Glade 2nd
10
      “         “         
  ok

050 - 075
32
      “         “          “            “
 good

075 - 100
27
      “         “          “            “
  good






100 - 125
16
Richard, Paul, Alan and Chiara
poor

125 - 150
20
     “        “         “           “
poor

150 - 175
20
     “        “         “           “
ok

175 - 200
32
     “        “         “           “
good

Bracken Patch
2
Richard and Paul
ok






200 - 225
66
Madeleine, George, Alan
v good

225 - 250
32
                          
v good

250 - 275
01
      “     “     “       “      “
   ok

275 - 300
10
     “      “     “       “      “
v poor

Shallow Pool
03

  poor






300 - 325
02
David and John
    ok

325 - 350
02
     “           “          “           “
  poor

350 - 375
00
     “           “          “           “
  v poor

375 - 400
01
     “           “          “           “
  v poor






400 - 425
01
Nikki
  poor

425 - 450
07
     “          “         “         “
  poor

450 - 475
07
     “          “         “         “
  poor

475 - 500
08
     “          “         “         “
  poor

       Total
483
This is the total written in diary on the day, after approximately 2 hrs



NB – Stephen and Anne Coker took GPS readings for all at end of December = 494
           Last year’s transect count total (2014) was 232