Black Hairstreak

It was a glorious summer day. I took Rosie to Thorpe Hall for an early morning walk, and found lots of bee orchids, a single pyramidal orchid, a large population of salsify and a single plant of motherwort - all growing virtually on our doorstep. When we got back I was going to tidy the house, but Chris announced the black hairstreaks were flying at Glapthorn Cow Pastures, and persuaded me to take him to see them. It certainly sounded more fun than hoovering!

The black hairstreak is one of our rarest butterflies and one of the most recently discovered, due to the similarity with its close cousin, the White-letter Hairstreak. This species was first discovered in the British Isles in 1828 when a Mr. Seaman, an entomological dealer, collected specimens from one of the most famous sites for this species – Monk’s Wood in Cambridgeshire. These were thought to be specimens of the white-letter hairstreak until Edward Newman, a Victorian entomologist of note, declared them to be black hairstreak.

This butterfly is not a great wanderer and an entire colony will often confine itself to a single area within a wood, despite there being suitable habitat nearby. The inability to colonise new areas at a pace in balance with habitat loss may partially explain the scarcity of this species. This butterfly has a very restricted distribution that follows a line of clays between Oxfordshire in the south-west and Cambridgeshire in the north-east.

When we arrived at the wood, a friendly photographer told us where the hairstreaks were to be found. We got there to find several other serious photographers already in residence. They didn't really acknowledge us, and when I spotted a butterfly and moved towards it, one particular man intercepted me and took loads of images until it flew off. I'm not sure whether he was deliberatley ignoring me or whether he was just oblivious - I hope it was the latter. Nevertheless I felt rather annoyed at his rudeness, and remembered why I'd never visited before. Chris and I decided to go and see what else we could find.

About 1.30pm it became very hot, which deterred the butterflies from nectaring for a while, although we were able to watch them courting high in the blackthorn bushes. The 'serious' photographers left and a group of more relaxed naturalists took over. Luckily for us, a bit of cloud cover encouraged them back down onto the bramble blossom, and we all managed to get photographs. Everyone was very considerate of other people, taking turns to get shots, and having enjoyable conversations in between times. It restored my faith in human nature!