Wednesday, October 4, 2017

Apatura iris in N Norfolk

On Monday I visited the valley in heavily coniferised woodland on the National Trust's Sheringham Park estate, near Cromer, where a lone Purple Emperor was seen last year and other sightings were made this year.
Although the area occupied by sallows in those woods is relatively small the sallows themselves are of very high calibre. Most of the sallow trees I saw there are genuine Goat Willow Salix caprea, which iris strongly prefers. It is actually quite a rare tree, and one which may be in serious decline in the heartland of the Purple Empire (replaced by hybrids). 

The Sheringham sallows had copious amounts of the type of foliage the females most strongly favour for egg laying, and on which first instar larvae fare best - leaves which are mid-green in colour, have non-glossy surfaces, and are of medium thickness.  

Elsewhere in that landscape, on areas of Boulder Clay, the sallows are mainly hybrids, though hybrids leaning towards S. caprea. They look good, very good (and I've found over a thousand eggs and larvae in countless hours of searching).

My guess is that the butterfly is moderately well established on clay lands between Cromer and Holt, or even as far east as Fakenham. I think North Norfolk is nicely Purple, I can't wait to return...

The Purple Emperor is, of course, Norfolk's premier butterfly...

No comments: