Hi Folks, migrantmad2
1stFeb'07

Sorry for any repetition, but what are the reasons for THIS winter's
wintering Rd.Adm's large population? There are several reasons, the
answer is not just "because it's a warm one" ! After all the Rd.Adms
were settled in (their winter sites) long before they read the weather
forcast.

For over 20yrs now I have known of overwintering sites, and watched them
become larger almost 'by the year'. Pontsmill was the first known to me,
and is still heavily populated. More generally, I know of over 10 sites
within a 5ml. radius of St.Austell, which are used annually but never by
so many as in the current winter. Thus for over 10yrs now many Rd.Adms
have presumably flown south on Sept/Oct 'emigration', and found Cornwall
to be a satisfactory northerly extention of the continent, thus staying
here to winter (and breed)!

How many? well the c.10sites I know of hold between 5 and 30 butterflies
each. Also many singles or 'pairs' winter in the same urban locality,
thus the total is WELL over 100+, THIS winter. The reasons seem
two-fold, the 'final' southward emigration, occured very late last year
(2006), mostly in October(due to a hiatus in 'up-country' breeding it
seems, some say most larva were parasitised by a continental(?) wasp) or
it may have been the weather, too hot! This perhaps meant the
sea-conditions were too bad for them to cross the Channel, OR a late,
warm, nectar-rich Cornwall tempted them to stay. Many of these factors
could be linked to Climate Change.

Furthermore, while I was out studying Cl.Yellows on 1stNov'06, I noticed
both at Pontsmill (morning) and The Gribben(afternoon), a very late and
very large IMMIGRATION of Red Admirals. Thus we had the would-be
emigrants and the late immigrants (now 'trapped' along S.coast), to
swell our wintering numbers. At least 30+ wintered in 'my' study garden,
and natural mortality seems to have been replaced by newly emmerged
individuals. Thus 'still' 20+!

Roger Lane migrantmad2
St.Austell