Monday 28th October 2013

The never-ending butterfly season?! Despite the extremely stormy weather we have been experiencing over the past 24 hours or so, I still managed to find amazing numbers of butterflies this weekend, and at times it felt as if summer was still with us. I headed down to my usual haunts in northern France, and on Saturday afternoon ventured out, first into the garden, where at least ten Red Admirals, Vanessa atalanta, and two Commas, Polygonia c-album, were gorging themselves on rotting plums on the ground. In order to warm themselves, they perched on the rushes surrounding a small pond, where they were sheltered from the blustery wind and could absorb the late-autumn sunshine at their leisure.

Although Red Admirals, like their cousins the other Vanessids (Tortoiseshells, Peacocks, etc), attempt to hibernate as adult butterflies, at least in the UK, whose climate is not that different to that of northern France, few survive the winter. It is interesting to compare the strategies of these closely related species. The Large Tortoiseshell, Nymphalis polychloros, disappears into hibernation in August, and even the warmest of autumn days will be unlikely to tempt them out. Small Tortoiseshells, Aglais urticae, and Peacocks, Inachis io, seem to hide away by mid-October, although I did see two Peacocks, one of which was disturbed from the garage, the majority of Commas have settled down for the winter, Painted Ladies, Vanessa cardui, attempt to migrate south for the winter or simply die, and yet these Red Admirals were just feasting on the rotting plums, without making any apparent attempt to either head southwards or to find a secure wintering spot. Could this be the cause of so few surviving through to the following spring?

The impressive showing of Red Admirals captured my attention for a while, but a trip to the Lac du Val Joly, a man-made lake not far away, was to prove far more impressive, with a walk through the grassy areas surrounding the lake revealing innumerable Clouded Yellows, Colias croceus, sheltering in the low vegetation or nectaring on the last of the flowering Knapweed, Centaurea nigra. There must have been more than 100 in just the three areas I prospected, including at least one of the pale female form var. helice. A lone Small White, Pieris rapae, was also to be seen here.

All in all, an unexpected autumn bonus - but still my annual list remains on 77 species, with little or no prospect of any further additions....but you never know!