Friday, 25 May 2018

in search of the green hairstreak pt2

On Monday 14th May there was another ranger-led walk in the Pentlands to look for more Green Hairstreak butterflies. Having had success the week before I initially wasn't going to bother, but with the forecast looking excellent again and being 2 different venues I signed up for more miniature green fun. The meeting point was Castlelaw car park which I have only ever run through between hills on the Skyline etc. So I hadn't realised there was a nearly vertical approach from the A702. Luckily I had given myself 75mins from Leith, and it took less than an hour. I had time to straighten my hair and dry the damp patches before kick off.

Turnhouse in the background

The walk was led by Victor Partridge and again I was impressed by his quiet enthusiasm for the wildlife and particularly the butterflies. The first stop was a field near the firing range which had been fenced off to protect the blaeberries (and hence the GH caterpillars) from grazing sheep. The farmer had allowed this despite the inconvenience, and after 3 or so years of no success they were on the point of abandoning the project, when green hairstreaks were then found there. Which shows the patience required: build it and they will come. Eventually. 

Almost immediately we were aware of the butterflies, even before we had got to the fenced off field. Below the field were gorse bushes which the (male) butterflies were using as look out posts to perch and proclaim as their territory. When others flew by they were set upon and spiralling dog fights took place. Often the butterfly would return to the spot he left. And being mostly yellow gorse flowers, this made for much clearer photos than last trip where the camera (and some of the observers!) struggled to see the tiny creatures and separate them from the background foliage. There seemed to be far greater numbers than last time as well which made them much easier to spot but more difficult to keep tabs on and identify just how many individuals we might be counting. Maybe 20+ ?

After we had passed between the gorse bushes we went into the field and spread out across the width to do a sweep up through the blaeberries. It was more likely that the females were feeding in the field while the males were doing their stuff on the gorse below. They are nearly identical. We found fewer butterflies in the blaeberries maybe about half or less than below. Victor kept a note of figures. 

One of Stewart W's favourite views

We descended from the firing range field and walked round to the second site, just below the path as you skirt round Castlelaw. Another south facing field of blaeberries. Again we fanned out and did a sweep but there were only a couple of butterflies here. However the sunshine and views made this a lovely outing and it was good to know Victor's efforts to promote the habitat of the Green Hairstreak were paying off and the butterfly seemed to be growing in numbers in recent years here. Albeit somewhat erratically. 

The group returned to the car park, however the sun was still shining and I was reluctant to leave without some more pics. I popped back up to the gorse where we had seen them earlier and spent 30mins taking more photos. Being unhurried I could take the time to engineer better backgrounds by moving the viewpoint to the best spot to get a bit of blue sky or blurred out yellow gorse to frame the little beauties. I was crawling over the ground on all 4s and cursing when they flew off in pursuit of another just as I had zoomed in. Equal amounts of joy and frustration and hundreds of deleted pics when I got home. They are so small you can't always tell which are sharply in focus and which are not, which show their cute little eyes and antennae and whether they have tattered wings from fighting or not. So as usual I take far too many and whittle them down later. You're welcome!...

males "fighting" for territory


Superb day out and I am already looking forward to the next Pentlands trip in a month or 2 to look for the Small Pearl-bordered Fritillary, which promises to be spectacular. Big thanks to Victor.

1 comment: