This is Dark Green, right?

[dilettante]

Taken at Arnside Knott a week or so ago. I think this is Dark Green, but I'm hoping against hope it may be High Brown. The third spot seems to indicate DGF though, right?

[David M]

I'd say that's a male High Brown. The upperwings are slightly concave and you can also see the raised sex brands.

The third forewing spot down is off line too in relation to the ones above it, which is what you'd expect to see in HBF.

Here's a High Brown male:



..and a Dark Green male:

[Padfield]

David is absolutely right - the sex brands are conclusive.

Guy

[dilettante]

Oh wow, that's great! I'm glad I asked now. Another new species for me then. Thanks very much Guy and David.

[MikeOxon]

My instinct when I saw your photo was that this was an HBF - concave wing edge and indented 3rd spot - but I decided to hold back for the real experts. Pleased to know I was right!

Mike

[David M]

but I decided to hold back for the real experts.

Please don't bracket me with Guy. He's forgotten more than I'll ever know!

I've spent a lot of time over the past two years scrutinising these two species when they've been flying together at Old Castle Down in S. Wales. I'm gradually finding it easier to tell them apart, although not nearly so well as the local transect walker, Paul Dunn, who can distinguish them in flight from up to 20 metres away!

[MikeOxon]

What is noticable is that, when I made regular visits to Arnside Knott several years ago, it was fairly safe to assume that the frits were HBF. Now, it seems that DGF are at least as frequent there and possibly in the ascendant. Is this evidence that the one species displaces the other?

Mike

[David M]

What is noticable is that, when I made regular visits to Arnside Knott several years ago, it was fairly safe to assume that the frits were HBF. Now, it seems that DGF are at least as frequent there and possibly in the ascendant. Is this evidence that the one species displaces the other?

Mike

I think a lot depends on the timing, Mike.

In early June, just about every large Fritillary at the S.Wales site was a Dark Green, but by the end of the month High Browns were pretty much on a par. When I last went on 26th July, again it was Dark Greens in the ascendancy (they must have a longer flight period - a bit like Meadow Browns which emerge before Hedge Browns and are still around when the latter have all gone).