2 Jul 2014

2 July 14 - Top Butterfly In Dorset

It's been a great day today. It's not unusual for me to break a day's birding into more than 1 post, but this is the first time I've posted more than once in a day. But I want to get these photos out as I know a number of locals will be trying tomorrow to see the goodie. So I'll jump ahead of the blog & cover an excellent afternoon at the nearby St Aldhelms Head. A couple of days ago, a mate George Green put out this intriguing email locally about some Swallowtail Butterflies locally at St Aldhelms Head. He had been out on a general walk with a non birding mate, when a couple clocked his bins & asked if he knew much about Butterflies. George replied yes & was then told they had seen a couple of Swallowtails. Quite rightly he suggested Marbled Whites were flying at the moment & then was told they had some pictures. A quick check revealed they had indeed seen a couple of Swallowtails. The original Butterflies didn't reappear in a short search, but the couple then found a third Swallowtail about 1/4 mile further along the footpath which they showed to George. This suggested that there had been a local hatch of the continental race of Swallowtail given there were 3 individuals. This is a vagrant Butterfly to Dorset. There have been occasional fly by records since I moved to Dorset 17 years ago, but I can't remember any records that have been twitchable over more than 1 day. Seem to remember there was one around at Portland a few years ago, but if so I don't think it was there for more than a few hours. Further information came out the next day that there had been other sightings in the previous couple of days before George's sighting. The result is I spent 5 hours up there yesterday looking without success. But it had been fairly windy on the headland with a 10 knot wind blowing. Today it was sunnier & less windy, so I decided to try again. As I walked along the coast path to where George saw his individual, I could see a large pale Butterfly flying over some purple Thistles about 50 yards ahead of me. I knew it was a Swallowtail as I was raising the bins & wasn't disappointed when I saw it. A quick jog got me to where it had gone down. It was still there.
Swallowtail: RESULT. It wasn't just me who was enjoying the sunshine
Given its rarity in Dorset, it's not been a species that I expected to ever see locally. Hence the reason why I had to return to try again today. It was quite mobile & disappeared for 15 mins or so at a time. It also seemed to be patrolling a territory along the clifftop path. I wasn't sure if it was also going onto the undercliff, but actually, I think it was moving further along the path. I had a patch of Brambles & Stinging Nettles which obscured my view to the further end of its territory & perhaps why it disappeared for quite long periods.
Swallowtail: This is the continental race of Swallowtails. The Norfolk population is an endemic subspecies & is darker than the continental population. The UK Butterflies website also states that the dark submarginal band on the wing tapers more in the UK subspecies of Swallowtail compared to the continental subspecies (however, it seems to taper on a number of the photos of the continental subspecies). Unfortunately, I've not got around to photographing the Norfolk population yet & on principal, I'm not going to resort to stealing somebody else's photo off the internet to illustrate the differences. But you can compare my photos with the excellent photos of the UK subspecies on the excellent UK Butterflies website
45 minutes after the first photos, I managed to get a third set of photos. Looking at these, I thought I was photographing a different individual as it only had 1 tail spike. But looking at the damage to the wing on the photos, I think it must been the same individual & it had managed to somehow loose its tail spike in that period.
Swallowtail: This was my final photograph. On several occasions, it was nectaring on the purple Thistles, but it was less approachable when feeding. But it was more approachable when it sat in the sun
Swallowtail: This was part of the 80 yards of so of territory it was patrolling
My last sighting of the Swallowtail was when I saw an old friend, Peter Williams, walking along the path. As I went to greet Peter, I saw it settle near the path between the two of us & it remained for several minutes, while Peter was getting some photos. Most of the local birders know Peter as he lives in a fantastic location in the nearby Worth Matravers & has been birding this excellent headland & set of valleys, including the famous Winspit Bluetail valley for the last 27 years. It was great to see Peter again & to spend a couple of hours talking about birds with him. It was a great end to a great day. I will do another post covering the other Butterflies photographed today, when I've caught up with the other recent sightings.
Peter Williams: Getting some shots of the Swallowtail - great to see you again Peter