Why does the Heath Fritillary only survive in two places?

[Danny]

So there is a colony in Kent, and a colony in Devon. How did this happen? Where there once colonies all over the UK and these are the two surviving pockets? or have they evolved independently (unlikly in my Opinion). If they are pockets of surviving Heath Fritillary, why do they only hang on there?

Now I hear that managing woodland helps butterflies like PBF and Heath Frit, through coppicing etc. But what about when man didn't coppice? Did the PBF exist before mankind managed woodland? Or does the PBF exist because mankind managed woodland? I would have thought that coppicing just mimicked the natural process of trees falling down, so therefore PBF and Heath Frit were flitting around before mankind did it's thing......though does this mean they were a rare thing in those days?

PS: Is there any difference between the Heath Frits in Kent and the Heath Frits in Devon?

Danny

[Pete Eeles]

Excellent question Danny. I've scoured my (ever increasing) library of books and Thomas and Lewington (The Butterflies of Britain and Ireland) offer an extensive explanation (to the tune of almost an entire page, just of explanation)! The essence of which is:

... Many thousands of years ago, the climate was much warmer (believe it or not!)

... And this species was able to survive in more overgrown conditions as a result (as it does, in fact, on the continent - Heath Fritillary were certainly the commonest butterfly I saw when I visited Hungary earlier in the year - they were literally in their thousands)

... As the temperature decreased, the species relied on more-specific habitat. In fact, this species was known to "follow the woodman" who would unknowingly create new, suitable, habitat through the practice of coppicing.

The specific requirements of this species weren't appreciated, and the species was on the brink of extinction in the UK (just behind the Large Blue). Fortunately, Martin Warren (now Butterfly Conservation's Chief Exec, and when at the Furzebrook Research Station) determined the exact requirements of the species, and specific conservation efforts saved this species from extinction. Of course, by then, the species was confined to a handful of sites.

Hope this helps!

Cheers,

- Pete

[Danny]

So i guess this is one of the species which will benefit from global warming. In the UK anyway. As the country heats up the Heath Frit will repopulate the land.

There are other weird things too, like the Brown Hairstreak stops going East at the West Sussex border. I mean why???? There are plenty of sloes in East Sussex and Kent, what goes on???

Also......talking Ringlet now. When I was a child growing up in Liverpool, I never saw a ringlet. Having Looked at the Millennium Atlas, I see there is a void around teh Mersey! Do Ringlets hate scousers????

Danny

[rdunn162]

Its not just Ringlets

[Pete Eeles]

As the country heats up the Heath Frit will repopulate the land.

With the decimation of wooded areas in the UK, I doubt this very much.

Cheers,

- Pete