www.ukbutterflies.co.uk

Searching for High Brown Fritillaries at the weekend in Cumbria has prompted this question. The only feature I have seen mentioned to differentiate between High Brown and Dark Green from above is the shape of the outer margin (convex in DG, straight or concave in HB). I found this very difficult to determine at most angles, and even ambiguous and variable when I was pretty sure I was directly looking down on a "flat" subject. Is this feature reliable ?
Anyone know any other ways of telling them apart from above?

My field guide by Wilkinson & Tweedie says of the dark green:
Very like the high brown but the silver spots on the hindwing underside are not surrounded with reddish brown and the basal half of the wing is dull green. The butterfly (dark green) inhabits more open country (high brown is a woodland species), chalk downs, moorland and coastal sandhills.

I guess that means check the underwing markings and the butterfly location.
HTH,
Eccles.

Thanks, but it's trying to find a reliable feature to ID them from above that I was looking for. They're obvious IF you can see the underneath of the hindwings, but that's often a very big if !

Their location is probably your best bet then. If it's seen in woodland the it'll more likely be a high brown.

Still catching up!

A fairly-reliable distinguishing feature, passed on to me by Alan Thornbury, is with regard to the dots toward the outside of the forewing (just inside the edge of the forewing).

In the Dark Green Fritillary, the first 3 are in a line. In the High Brown Fritillary, the 3rd dot is either displaced or missing.

Hope this makes sense!!!

Cheers,

- Pete

Myself and three friends were in Cumbria on Sunday, we visited Gait Barrows and as soon as we started on the Yew Trail had two 'probable' H B Frit on brambles in the sunny open areas of the trail. We only saw the uppersides and very briefly as we found they weren't approachable.
We were also searching for N B Argus which we failed to see.
Eventually we found a couple of definite H B Frit which we could see the underwing markings. I got a couple of photo's of the upperwing see here


[/img]

Compare this to the upperwing of one of the many D G Frit we saw at Arnside Knott last year on bracken in the very open area.



I still found it difficult and was only happy when I saw the unmistakeable underwing pattern of the H B frit.



We however also saw D G Frit in the wooded areas at Gait Barrows.
We did try for Mountain Ringlet at the Wrynose Pass site but in perfect conditions a two hour search revealed only masses of Small Heath and a few Golden-ringed Dragonfly.

I was really struggling to find the NB Argus at Bishop Middleham Quarry in Durham, spent quite a few hours there.

It wasnt until my second visit that I thought I would search the Rock Roses more closely, and sure enough there was quite a few of them.

I had missed them because I didn't realise how small they were.

I was shocked how tiny N.B Argus were too Wayne, and agree they could be easily missed!

Thanks for the ID pointer Pete.that was exactly what I was hoping for but I'm still not totally clear on which spots you mean. Did you mean the first 3 dots from the front or rear edge of the forewing ? If you mean from the front, then on the photo taken by Tufty of the High Brown , it seems to show a large spot very near the edge, then two large spots in a row then a small displaced spot. But does the spot very near the edge count ?!

Here goes ...



Cheers,

- Pete

Brilliant ! Thanks Pete.

Yes thanks again Pete, I have never been able to pick out the differences that ID guides tell you to look for.