Clouded Yellow survive UK winter

[Morten DD Hansen]

Hi out there!

I don't understand why the possible overwintering of the migratory specie=
s Vanessa atalanta, V. cardui and Colias croceus has drawn so much attent=
ion during this century. If long-distance re-migration was not the most s=
uitable strategy for these butterflies, selection would act against it...=
=2E But the butterflies perform seasonal unidirectional migrations in hug=
e numbers!!! I believe that only lipid depleted or late emerging butterfl=
ies 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 Van=
essa atalanta \plain\f4\fs20\cf0 capable of surviving the entire winter i=
n the UK, both as an adult (as many suspected) and as larvae. Last year 1=
997/8 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 f=
ar to sensitive to frost to survive, could in fact remain alive as an adu=
lt from late October until May, given benign conditions in the SW of Engl=
and. \par Now comes evidence that Clouded Yellow \plain\f4\fs20\cf0\i Col=
ias croceus \plain\f4\fs20\cf0 ova laid in November on England's southern=

> coastal fringe not only grew throughout the winter pasing through all t=
heir stages until eventually pupating but have now emerged and laid ova o=
f their own. The initial observations were made by Michael Skelton who ke=
pt a close eye on the small colony of larvae and as word got around sever=
al others were able to confirm the sight of larvae feeding through the mi=
lder winter days and more recently of up to 8 individual adults flying ab=
out at the site. The almost complete lack of other migrants so far this y=
ear 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\c=
f0 today, \plain\f4\fs20\cf0 certainly too far away for there to be a lik=
elihood of this singleton being from the same source. Possibly this indiv=
idual is from another overwintering colony; perhaps not on the UK mainlan=
d but one of the milder southern islands like the Channel Isles or the Is=
les of Scilly; where frosts are almost never felt.
> \par \par As in England all the migrant species are especially scarce i=
n France and Spain (our presumed source of the great majority of adults r=
ecorded here in spring) so far this year. \par \par Any other news of unu=
sual sightings of species normally considered to 'soft' to live through o=
ur northern winters would be greatly appreciated. \par \par Conservation =
Officer for UTB\\ Butterfly Conservation \par 94 Miswell Lane, Tring, Her=
ts 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/