After a reasonable attempt at spring the over the last few
days that has seen me clock up all the 5 normal hibernators, the weather has
turned and Lepidoptera once more seem a rather distant and frivolous summer
thing, and as such, it’s time to burn the swiss midnight oil afresh.
BVW roosting. |
The ‘Whites’ is a bit of an amorphous term that I tend to
apply fairly freely to anything in the first 80 pages of Tolman &
Lewington, hardly a monophyletic group, but convenient. This includes
Swallowtails, Apollos, Festoons, Brimstones, Clouded Yellows, and then at some
point actual whites. Over the course of the walk, we notched up 17 species in
this fairly arbitrary group, with the commonest probably Black-Veined.
Acrobatic copulation from BVWs |
Despite their relative abundance, I always find these
butterflies strangely thrilling, a little piece of Old England flying by on
their papery wings. Black-Veined Whites became extinct in the UK in the 1920s,
with the failing of the last Kentish populations, a string of releases has
followed since, famously by E. H. Newman in the grounds of Churchill’s
Chartwell estate, and most recently, a clandestine introduction to Stockbridge
Down resulting in trampling of some of the site’s key habitats by ardent
photographers – a cautionary tale about the use of such releases if ever there
was one. The causes of extinction are poorly known – Colin Pratt’s ‘Modern
review of the Demise of A. crataegi L., the Black-Veined White’ notes a string
of wet Septembers tended to precede extinctions on most sites, and the cries of
many frustrated breeders of the time who suggested an increase in passerine
populations (due to shotgun innovations=fewer raptors=more blue tits=more
predation of larval webs and pupae). In essence, it’s far from an open and shut
case.
Mountain Green-Veined White at roost. |
Following the veined motif, Mountain Green-Veined Whites
became one of the commonest butterflies at higher altitudes, and despite being
very active in sunny conditions, were relatively easy to find and photograph
when at roost on flowerheads. These differ from ‘our’ Green-Veined Whites by
having heavier, greyish streaking, and often more of a dark suffusion.
Interestingly, they have this in common with Scottish, thomsoni Green-Veined Whites – a nice bit of convergent evolution,
adapting to their common struggle against frequent colder spells.
Having looked back through my photos from the trip, it’s
clear I didn’t pay perhaps as much attention to the whites as I should have,
with only a few photos of Mountain Clouded Yellows and their kin, probably
because most of it was lavished on one particular set of broad white wings –
Apollos. These are arguably one of Europe’s most impressive butterflies –
ardent brits might choose the Purple Emperor for its dazzling iridescence, and
aloof, regal nature, yet Apollos are amazing in a different kind of way: ethereal, seemingly detached, gliding past on wings so large and papery it’s
possible to locate them as they soar past the back of your head, purely on the
basis of the rustling they make as they move, and for such a butterfly, an
iconic setting is a must, so snow-capped peaks and sound of music meadows it is – they,
like most alpine butterflies, are a sight it’s hard not to be seriously
impressed by.
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