Monday 9 August 2021

New butterfly for Norway!

As my more regular readers will know I have a growing interest in butterflies which has really taken off in the last 3 years. Many birders develop this interest plus one for dragonflies as the hot summer months are a quiet time on the birding front yet a good time for insects so our interest is drawn to the most bird like insects there are.

I have confined my interest in butterflies to just recording the ones I see on my regular birding trips and have only once travelled to specifically look for new butterfly species which was a complete flop as can be read here. Never-the-less I have now seen (and all are self-found) 60 species in Norway out of what would be appear to be a total list of 100 species. This compares to my bird list of 316 species (281 self-found) out of 505 species. The stats therefore quite clearly make me a far more competent butterflyer than birder! 😊

This year I have had a bit of a focus on finding Hairstreaks in and around Oslo and have had quite a few sightings of White-letter (alme-), Purple (eike-) and Brown (slåpetornstjertvinge). The Brown Hairstreaks have been particularly photogenic whilst nectaring whilst the other two have always been annoyingly high up in trees. I have therefore been drawn back to the Brown Hairstreaks a few times. As I am seeing them at Fornebu which in addition to being good for birds also has a dog park I was able to persuade Mrs OB that we should make a trip there with the Beast on Saturday. It was initially a bit cloudy but after the sun came out I spent some time looking downwards whilst my better half power walked the dog.

I was a bit distracted from butterflies by a Great Snipe which I disturbed from long grass and managed some good flight shots of this scarce local passage bird.

My target butterfly species showed well though and I got to see 3 female and 2 male Brown Hairstreaks which allowed me to appreciate that they can be separated on the underwing and not just the upperwing. I also saw Small Blues (dvergblåvinge) from what in Norway is a very rarely recorded second generation. The only other blues were Common Blues (tiriltungeblåvinge) which were common but came in such a variety of sizes and hues that I found myself looking at each one to confirm identity.

A particularly large blue butterfly caught my attention and I followed it until it landed. Through the camera I saw it had tails! My initial thought was that maybe I was looking at a strange colour aberration of a hairstreak but I then saw its underwing and realised that was not the case at all and this was something new and different. The tails were VERY long and the pattern of the underwing just screemed exotic! I only know of a single species of blue butterfly with a tail and remembered seeing pictures here on Peter Law's excellent blog. A quick google search confirmed that I had indeed found a female Long-tailed Blue! And a further search revealed no other published Norwegian records and also that it had no official Norwegian name!

The pictures I got were rather good and the butterfly was in pristine condition. The species is a long distance wanderer and is appearing in the UK in greater and greater numbers. Oslo is however a lot further north than any other records and the possibility of it having arrived “unnaturally” has to be considered. Apparently caterpillars of this species are known to be found in peas (mangetout) imported from Kenya so there is the possibility that someone has found a caterpillar and thrown it out into their garden and it has then pupated and emerged? I don’t know whether a genuine migrant or an imported caterpillar is more likely but have I enjoyed in bathing in all the congratulations I have received on Facebook for finding a new species for the country 😊

I have read that butterflies develop tails as a defence mechanism against birds. Birds think that the wings are the head of the butterfly and therefore try to grab at that end. As they are part of the wing they easily break off allowing the butterfly to escape. This explains why lots of hairstreaks are missing their tails but of course it is a defence strategy than can only be used once. My pictures of the Long-tailed Blue whose tails were still intact (which suggests she emerged recently) show that she was moving them around a lot presumably all as part of the act to fool predators.

female Long-tailed Blue - just look at those "tails"


and looks how the tails can be moved around









Brown Hairstreak (slåptornstjertvinge) this female has lot its "tails" and a lot of tis wing to a bird but has escaped alive

another and immaculate female
and here a video grab showing the upperwing. Females have the red mark which is lacking in the males I have previously pictured 

and a third female. Compare to the male in the next shot. The underwing of the female is more brightly coloured and the tails perhaps slightly longer

a male Brown Hairstreak (sex confirmed by seeing upperwing)


Small Blue (dvergblåvinge) is not a species I see often but a number of my records have been of the rarely recorded second generation



mating Common Blues (tiriltungblåvinge) taken with the bazooka from 2.5m away

and with an iphone 8 at about 10cm



a noticeably pale male Common Blue

it is not often that a Great Snipe (dobbeltbekkasin) is relegated to last place in a blog post ;-)






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