Chalkhill Blue
I have to travel a long way south to see Chalkhill Blues because they are confined to chalk and limestone sites in the south, with north Norfolk being their northern limit (and I live in Yorkshire). I don't see them very often but my experience is that they were usually the commonest species in late July and August on downland sites. But apparently not any more as they are declining. BITH (www.flickr.com/photos/99303089@N00 ) tells me that in Dorset they were once widespread and are now virtually confined to Portland where they occupy disused quarries. He thinks, and I agree that this may be down to lack of grazing as the caterpillars need short vegetation in which to feed. Apparently longer vegetation makes it cooler at ground level.
I photographed this one at Barnack in Cambridgeshire where it seemed to be common, though it was my first visit so I have no yardstick. But I only saw them in areas with short vegetation. I found them hard to capture with wings open as they were usually obscured by grasses with a cluttered background. I used my telephoto lens (300mm with 1.4x converter f5.6) for this shot but it has captured the wing scale detail. There is no other blue butterfly in Britain quite like Chalkhill as they are a really pale colour with that row of black spots on the hindwing margin. I say black, but if you look really closely you can see they have a bit of orange (like a female has). But because I see them so rarely I'm not sure how frequent this is. Though among my few photographs of this species on Flickr I do have another that shows orange spots here: www.flickr.com/photos/timmelling/5990993257/in/photolist
Chalkhill Blue
I have to travel a long way south to see Chalkhill Blues because they are confined to chalk and limestone sites in the south, with north Norfolk being their northern limit (and I live in Yorkshire). I don't see them very often but my experience is that they were usually the commonest species in late July and August on downland sites. But apparently not any more as they are declining. BITH (www.flickr.com/photos/99303089@N00 ) tells me that in Dorset they were once widespread and are now virtually confined to Portland where they occupy disused quarries. He thinks, and I agree that this may be down to lack of grazing as the caterpillars need short vegetation in which to feed. Apparently longer vegetation makes it cooler at ground level.
I photographed this one at Barnack in Cambridgeshire where it seemed to be common, though it was my first visit so I have no yardstick. But I only saw them in areas with short vegetation. I found them hard to capture with wings open as they were usually obscured by grasses with a cluttered background. I used my telephoto lens (300mm with 1.4x converter f5.6) for this shot but it has captured the wing scale detail. There is no other blue butterfly in Britain quite like Chalkhill as they are a really pale colour with that row of black spots on the hindwing margin. I say black, but if you look really closely you can see they have a bit of orange (like a female has). But because I see them so rarely I'm not sure how frequent this is. Though among my few photographs of this species on Flickr I do have another that shows orange spots here: www.flickr.com/photos/timmelling/5990993257/in/photolist