Small Pearl-bordered Fritillary - Favourite Photo of 2023

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Roger Gibbons
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Roger Gibbons »

Surmising somewhat, given that we don’t know the thought processes that led these two experts to conclude selene without qualification, but I would think that they went unequivocally for selene largely on the grounds that there was no chance dia flew there and that the ups was within range for selene. Else, I would have expected them to have said that it could only be selene on the grounds of location. Didn't Sherlock Holmes say something about "once you have eliminated the impossible" (not that I've seen his record on Boloria ID)?

I think it highly likely that without the location they would, as we did, have said dia with little doubt.

This raises an interesting question about identification. It is usually most useful to give an image blind, or even double-blind where you don’t even know who gave it to you. That at least inhibits getting an ID based on where rather than what.

It raises the question, though, that if the circumstantial evidence such as location would aid the process of coming to a more accurate conclusion, would it be helpful to withhold it? I guess it depends on who you are asking. I spent a full day (10.00-20.00) of species analysis with these two experts and they clearly weren’t the sort of people to make off-the-cuff judgements (would have been a shorter day if they had).

Maybe the best approach would be to give an image blind, get an opinion, and then say where and when, and ask if that changes their opinion, not so easy when we communicate by email.

I get a lot of ID requests and I give an opinion based on what I see as the evidence, which I state (maybe a hangover from those teachers who told us to put our workings in the margins). Quite often this arises because someone hopes their image is a rare species (often in the Pyrgus field) and I have to give the honest answer that is often the common(er) species. It is almost Occam’s Razor territory. I do sometimes get the reaction of disappointment and occasionally disbelief.

I concur with your last paragraph, Benjamin, in that it appears that dia and selene can look identical if this image is within range (rather than "a familiar look") for selene. I don’t think we’re missing some ups ID clue. This issue of “within range” comes up so often in the thorny issue of Pyrgus ID. Quite often I give a view that, on the balance of probabilities, an image is 80% likely to be xyz, and I welcome other inputs.

Tristan Lafranchis’ book subtitle was “identifying butterflies is easy”. I’m waiting for his next book “if you don’t understand general relativity, you must be a bit thick”. :)

Roger
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bugboy
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by bugboy »

Ok, just to throw a little (tiny) spanner in the mix (and I freely admit I may be seeing what I want to see) there does look to be the barest hint of the top edge of the hindwing on the right hand side which does give the impression of being sharply angular?
Boloria selene_51490W.JPG
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petesmith
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by petesmith »

bugboy wrote: Fri Feb 09, 2024 7:29 pm Ok, just to throw a little (tiny) spanner in the mix (and I freely admit I may be seeing what I want to see) there does look to be the barest hint of the top edge of the hindwing on the right hand side which does give the impression of being sharply angular?
Boloria selene_51490W.JPG
That's a very acute ( :wink: ) observation bugboy, and possibly very significant. I am now contemplating reviewing all of my Weaver's and Small Pearl-bordered photographs when I get a chance. As others have commented I would have instantly considered Roger's Small Pearl-bordered to be Weaver's and not given it a second thought.

The hazards of assumptions...
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Wurzel
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Wurzel »

Matsukaze wrote: Thu Feb 08, 2024 9:33 am
Wurzel wrote: Sun Feb 04, 2024 6:25 pm Small Pearl-bordered Fritillary

With the Bentley Wood Small Pearls now sadly gone I once again had to make the trek to Priddy Pools for my fix of this species. However they seemed to be having a lie-in this year and when Philzoid and I first visited none were found and we had to make up for their lack with Glanvilles instead. On my second visit they were all over the place. The usual spot was quite productive but the end of bank that runs parallel held crazy numbers! Whilst this was great, the warmth and the activity meant that getting underside shots was very difficult. However I eventually got lucky and one individual sat feeding for some time in a lovely position and so I was able to get my Favourite shot of the year.

SPBF 1.1 10-06-2023a 22.JPG

Have a goodun

Wurzel
I may be misreading this, but are you saying that there were Glanvilles at Priddy last year?
Sorry I wasn't very clear. We called in at Whitesheet on the way home for the Glannies which offered compensation for the lack of Small Pearls at Priddy. Interestingly though there have been reports of Marshies from Priddy so eventually there may be some Glannies if the Frit dumper continues their activities...

Have a goodun

Wurzel
Benjamin
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Benjamin »

Very well put Roger.

Whatever conclusion we each come to, I’m sure we can all agree that working through these puzzles is an incredibly useful and enjoyable way of sharpening ID skills!

I do still think it’s dia - just because it looks like one and I can’t find any images of selene that do enough to sufficiently muddy the waters. I am, of course, aware that to many this apparent irreverence is unbecoming, so in an attempt to defend my position I will just say that the local expert opinion did move my scales in the direction of selene but just not enough to tip them from one side to the other.

I’m sure I can’t really justify this position, but I can live with that.
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Matsukaze
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Matsukaze »

Thanks Wurzel. Hopefully the Glanvilles will still be there in 2024 - in truth I'm surprised they have lasted that long, as their populations seem to struggle to survive on chalk downland.

I've seen Marsh Fritillaries a couple of times at Priddy, and they certainly used to be resident there 25 years or more ago. The butterfly is a bit intermittent in appearance there and the feeling locally is that the ones that turn up there now are being released.
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Roger Gibbons
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Roger Gibbons »

I have looked in detail at my photos of dia and selene and, although I have some selene with a “degree” of angularity i.e. some sort of angle, I don’t have any that have the sharp angularity of this one. Well spotted bugboy!

I think it is almost certainly dia. I have said that but left it on my selene page with the narrative from these UKB pages in order to elicit comment, working on the basis that comment is more likely if someone thinks it’s in the wrong place.

I have looked at the records for the region, and there records in excess of 1400m, so this altitude is not out of range for dia.

That just leaves the questions:

Why are there no records of dia from the region of the Col de Finiels, especially given that it is a key site for certain highly localised species, and thus well surveyed?

Why have I not seen dia there before, given the number of visits I have made there (there may be a simple answer to this, of course)?

Why did the two French experts immediately opine for selene? I’ll probably meet up with them at some point when I can have a more detailed discussion than email would permit.

In the late 1990s I took a photo near Bordeaux of what I then thought was a Ringlet (Aphantopus hyperantus). It was some years later when I was looking over these old photos (in the old days they were actually printed on glossy paper) and it became obvious that it was actually the rare and localised False Ringlet (Erebia oedippus). Aaaargh…

Roger
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by Padfield »

I'm a little late to the party, but I am sure Roger's butterfly is dia. Apart from all the things already mentioned, the antennae are wrong: they are conspicuously black and white in selene and a much less contrasting dirty colour in dia.Together with wing shape, markings &c. &c. I don't see any real chance of it being other than dia.

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David M
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Re: Small Pearl-bordered Fritillary - Favourite Photo of 2023

Post by David M »

....and now...for something completely different...

..taken on 2nd June, this female SPBF was one of very few I saw locally last year:
2.SPBFfem(1).jpg
2.SPBFuns(1).jpg
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