Photographic Advent Calendar, Day 15: Painted Lady

The Painted Lady (Vanessa cardui) is a smart lepidoptera species that is highly migratory, and can often form large influxes involving tens of thousands of individuals. Every year this species repeats its migratory cycle, starting off in the northern reaches of Africa and the Middle East, moving north through Europe and arriving in the UK as early as March. These first migrants will lay their eggs, giving rise to a second generation around August time; occasionally there may be more than one brood in the UK, depending on the weather. Some of these second generation butterflies can make it as far as the Orkney and Shetland Isles. Indeed, the Painted Lady is said to be the only butterfly species ever recorded on Iceland.
Ultimately, the fate of most of these migrants is that of premature death, as the winter conditions in this country are too harsh for the Painted Lady to overwinter in any part of the life cycle. Some individuals are thought to attempt the autumn migration back south, but it isn't entirely clear what proportion make this move.
Thistles, Mallows and Common Nettle make up the bulk of the larvae's foodplants, although adults will feed on any high-nectar source to fuel their continual movement. The last large influx of Painted Ladies was in 2009, when even on Bardsey I can remember counting hundreds streaming through every hour- an amazing sight. 2015 has been a good year too, with particularly high numbers feeding on the coastal thrift in June.