Hibernating Red Admirals, how common are they?

[Africa]

I have been recently looking at the butterfly records submitted to the UK Phenology Network. This is an invaluable resource which is used to produce scientific papers related to global warming. I read time and again that the Red Admiral cannot survive our winter and that each year it migrates from mainland Europe. I compared the first sightings of Red Admiral with the first sighting of Small tortoishells, an hibernating butterfly in the UK with a similar distribution. These are the data. All are number of first sightings of individuals active before 1st of March:
2008: 115 Small Tortoishell, 126 Red Admiral
2007: 135 Small Tortoishell, 540 Red Admiral
2006: 27 Small Tortoishell, 95 Red Admiral
2005: 39 Small Tortoishell, 47 Red Admiral

This shows that the numbers of these two species turning out in the winter are similar, if not higher for the Red Admiral. More interestingly, when you look at the exact dates, both species appear at the same days - most likely coinciding with fine winter days - when hibernating individuals come out to sun themselves or briefly feed on early flowers. A migrating species would turn out later in the season and not at the same time than a hibernating one. The distribution of these first sightings of Red Admiral is all the southern half of the UK, up to Yorkshire and even some more northern sightings. In Janueary 2007, in a very windy and cloudy day, I spotted a Red Admiral flying in the centre of Hull: the wind possibly disturbed it enough for it to fly and re-settle at a different spot. Another fact that makes me think the Red Admiral is a regular hibernating butterfly is that they are very 'cold resistant' and usually one of the last butterflies to be seen in the year, happily feeding on Ivy flowers up to early november. I just wanted to bounce these ideas and see how many of you think we should stop thinking of this species mainly as a migrant.

[Dogghound]

I know that red admirals hibernate in my garage in North yorkshire as I find plenty in their through the winter and as it warms up I find them trying to get out at the window and door so have to help them out.

[ron1863]

What I know is that some do overwinter here but not all survive.
I saw a Red Admiral in February this year on a beautiful sunny day but doubt that it survived as it was really bitter that night. Apart from that sighting I have only seen one other Red Admiral this year.

[village wench]

Could these be red admirals ? hibernating on my shed back wall,they have overwintered there for several years now,generally don't start to flutter about until roughly mid march.

[Dogghound]

There Small tortoiseshell

[aeshna5]

Certainly the winter before last there were large numbers of over-wintering Red Admirals down in the south + frequently saw them frequently on mild days through that winter. This of course followed a good summer with near record numbers of insect migrants.

By contrast last summer, like this one was fairly dire + few migrants. Last winter I saw only a couple during the winter.

It does seem to be, in general, to be increasing as a successful winter resident, but is probably still dependent on immigration. It has also been proved to overwinter successfully as larvae, though I don't know how widespread this is- more likely in mild winters.