I started my last post by saying I thought it would be my last butterfly post of the year and I did expect that to be the case but that post in itself has spawned definitely this post and probably another in the hopefully not too distant future.
So, my last post detailed me having seen an Essex Skipper (timoteismyger) Thymelicus lineola which was new for me in Norway and also a small range expansion with it being the first record in Bærum which is the municipality immediately west of Oslo. As I hope I made clear I was very happy with this record and in addition to writing about it on the blog I had written a post on the Norwegian Facebook Group "Sommerfugler i Norge" detailing the range expansion and had reported it on the Norwegian biodiversity website Artsobservasjoner where I had even gone to the rare step of highlighting it by using the red "interesting comment" function.
This is the butterfly in question:
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| a Skipper (smyger) but is it Small or is it from Essex? |
It was my post on this blog though that would prove to be the most important. On Friday I was rung by an unknown number from Denmark but was unable to take the call. However, the caller, John Faldborg, left a message saying that he was calling about something on my blog and that it was in my interest to hear what he had to say. Interesting stuff indeed and early the next morning John called me again and this time I (eagerly) answered. The excitement in John's voice was clear as was the fact that he had gone to the bother of finding my number and calling me rather than sending a message. The reason for his excitement? Well John was quite certain that my photo of an Essex Skipper was in fact of it's twin species Small Skipper (okersmyger) Thymelicus sylvestris.
Small Skipper has never been recorded in Norway, nor Sweden as far as I can ascertain, but does occur in Denmark where it flies alongside Essex Skipper (as is also the case in England and most of Europe). Now Essex and Small Skipper are VERY alike and the safest way to separate them is the colour of the underside of the bulbous tip to the antenna - one species is orangey and the other blackish. Given these are tiny species with a wing span of only around 25mm then it is clear that seeing the colour of the antenna tips requires a magnifying glass or good picture - which I had luckily (and unusually for me 😉 ) taken. I was aware of this difference from my forays into butterflies over 30 years ago when still living in Southern England and had noted on my photo that the butterfly had orangey tips. I couldn't remember which one of the twin species had the orange tips but that was of no consequence as we only have one of the species in Norway and that is Essex Skipper so obviously it was Essex..... For me the only ID question had been ensuring it wasn't a Large Skipper (engsmyger) Ochlodes sylvanus and that had been straighforward.
I am flattered that John finds this blog interesting enough to read and for him who lives where both species are found and need to be differentiated then the orange shouted Small Skipper. He could also see small differences in the patterning of orange and black on the wings that were better for Small than Essex. A Danish butterflying friend had also agreed with his ID (based on the one photo). The individual I found can be seen to be a female as it lacks the black sex brand on the wing that males have - had it been a male then the shape of this stripe would also have been an ID feature as it differs between the two species. You can read about the separation of the two species on the Butterfly Conservation website where it also says "Because of the similarities, the Essex Skipper has been overlooked both in terms of recording and ecological study, and it was the last British resident species to be described (in 1889)." If they took so long in Blighty to recognise it when there was so much specimen collecting going on then it is clear how difficult an ID challenge it is.
John's excited phone call definitely helped wake me up on Saturday morning far more than the coffee I was drinking and set me in motion reaching out for second, third and fourth opinions.
I was of course a bit embarrassed with myself for not having realised the significance of the orange antenna tips but can at least console myself with the fact that no other Norwegian who saw the picture on Facebook or Artsobservasjoner reacted either. And why would we? When Small Skipper does not occur here and has never appeared on any list of expected new species.
First was an email to the person responsible for the butterfly collection at the Norwegian Natural History Museum who would ultimately be responsible for accepting a new butterfly species on to the official Norwegian list. Second was this post on Twitter (X if you must) to see if there are still any decent folks (rather that right wing trolls) using it who would give an opinion.
The responses came in surprisingly quickly and my email to the Museum was forwarded to the greatest butterfly minds in the country (two other people 😀) where the response was extremely positive. Twitter also gave positive responses in terms of "well it has to be a Small Skipper doesn't it because it has orange antenna tips". One of the (three) positive Twitter responses was also as you can see from Richard Lewington who illustrated the Collins Butterfly Guide to Britain and Europe.
So, the ID should be straightforward but there is one small fly in the ointment.Both Per Kristian Slagsvold at the museum and @cryptidbirder on Twitter pointed me in the direction of this picture on lepiforum. It is a picture that shows an Essex Skipper with orange tips. This picture would seem to throw the whole ID feature into disarray. One might ask how can we be certain that it is an Essex? As it is a picture I assume there is no specimen or Dna but the picture is taken in Canada and Essex Skipper is an introduced species to North America (in 1910) but Small Skipper does not occur - which should make the ID certain. But this does raise more questions.
Why is there just this one picture (that I am aware of) showing Essex with orange tips and why is it from an introduced population? In the areas of Europe where both occur (which is basically the whole range except Norway, Sweden and Finland) one can assume that any skipper photographed with orange tips will be instantly identified as Small and no further thought paid to the matter. So maybe there are more Essex Skippers with orange antenna tips but they are filed away under Small? A thorough search of Norwegian, Swedish and Finnish pictures would help here to determine whether this "abberation" does occur in Europe and I will try to do that search.
Another explanation is that the introduced North American population comes from such a small gene pool that abberations will be more likely?
I don't know the answer and neither will it be me that makes the final decision as to what I photographed. Per Kristian from the museum drove an hour today to join me to try to find it again or hopefully more (the one I photographed was so fresh that it was likely locally bred and therefore part of a population). We did not find any but as PK said - I wouldn't have driven here to search if I didn't think it probably was one. The museum collection does included Small Skippers collected elsewhere in Europe and these will be studied but I expect that without further observations, better photos from all angles and most likely a specimen or two (from which Dna can be taken) that an official decision will not be taken. However that remains to be seen which is why I wrote I hope that I will be writing a further post on this one single flutterby....
So if it is a Small Skipper (which it would without hesitation be identified as such in all countries where it is expected to occur) then how did it get here? Well butterflies do fly, warm winds have been from the south and the northern tip of Denmark isn't that far away. The day after my Skipper sighting a vagrant Clouded Yellow was seen nearby and there have been records of vagrant southern moths so it ain't an impossible record.
Two footnotes:
1. Should this be accepted as a new species for Norway then it is John Faldborg who should get all the honour.
2. The location where I saw it is only 300 metres from where I found Norway's only "wild" Long-tailed Blue although the general view seems to be that this has to be a butterfly that originated as a caterpillar in imported peas from Kenya. But we can never be sure - maybe Fornebu has some magical attraction to rare butterflies?
