Clouded Yellow survive UK winter

[Nigel Venters]

Good point except how could selection act against migration if no genes
from the migrants ever returned to the gene pool?
Nigel

Morten DD Hansen <biomddh at biology.au.dk> wrote in article
<3739A4D6.79A8B30A at biology.au.dk>...
Hi out there!

I don't understand why the possible overwintering of the migratory species
Vanessa atalanta, V. cardui and Colias croceus has drawn so much attention
during this century. If long-distance re-migration was not the most
suitable strategy for these butterflies, selection would act against it....
But the butterflies perform seasonal unidirectional migrations in huge
numbers!!! I believe that only lipid depleted or late emerging butterflies
try to overwinter.

best regards
Morten DD, Aarhus, Denmark

Nick Bowles wrote:

> Recently MIke Tucker has shown the Red Admiral \plain\f4\fs20\cf0\i
Vanessa atalanta \plain\f4\fs20\cf0 capable of surviving the entire winter
in the UK, both as an adult (as many suspected) and as larvae. Last year
1997/8 Prof. John Wacher was able to provide evidence that a Painted
Lady\plain\f4\fs20\cf0\i Cynthia cardui\plain\f4\fs20\cf0 widely regarded
as far to sensitive to frost to survive, could in fact remain alive as an
adult from late October until May, given benign conditions in the SW of
England. \par Now comes evidence that Clouded Yellow \plain\f4\fs20\cf0\i
Colias croceus \plain\f4\fs20\cf0 ova laid in November on England's
southern
> coastal fringe not only grew throughout the winter pasing through all
their stages until eventually pupating but have now emerged and laid ova of
their own. The initial observations were made by Michael Skelton who kept a
close eye on the small colony of larvae and as word got around several
others were able to confirm the sight of larvae feeding through the milder
winter days and more recently of up to 8 individual adults flying about at
the site. The almost complete lack of other migrants so far this year helps
to make their 'native' status claim more likely. The only other Clouded
Yellow record that I know of is from SW England \plain\f4\fs20\cf0 today,
\plain\f4\fs20\cf0 certainly too far away for there to be a likelihood of
this singleton being from the same source. Possibly this individual is from
another overwintering colony; perhaps not on the UK mainland but one of the
milder southern islands like the Channel Isles or the Isles of Scilly;
where frosts are almost never felt.
> \par \par As in England all the migrant species are especially scarce in
France and Spain (our presumed source of the great majority of adults
recorded here in spring) so far this year. \par \par Any other news of
unusual sightings of species normally considered to 'soft' to live through
our northern winters would be greatly appreciated. \par \par Conservation
Officer for UTB\\ Butterfly Conservation \par 94 Miswell Lane, Tring, Herts
HP23 4EX tel 01442 824 407 \par }

--
Morten DD Hansen, stud. scient.
Dept. of Zoology, Institute of Bioloical Sciences
Building 135, University of Aarhus
Universitetsparken, DK-8000 Aarhus C
Telephone: +45 8942 2695
e-mail: biomddh at biology.au.dk

homepage on migrating birds and butterflies:
http://www.biology.au.dk/~biomddh/



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