padfield wrote:In answer to David's post: I don't want to add much because I don't really know any more than I've already said. There are experts in this domain and I'm not one of them. However, I was thinking, as I wandered the vineyards this autumn and winter, how different the climate is here from in England. It's not the warmth or cold - but something more profound. On December 11th the ambient temperature was well below freezing in the morning and never reached higher than about 4° C in the early afternoon. But the sun brought out Queen of Spain, clouded yellow, wall and red admiral. Lizards were scuttling about and flies and bees were buzzing. Now, a week later, the whole thing is buried under deep snow. Last year there was a six-week period when the valley snow never melted. It does seem to me that the UK's long, mild, often damp, winters, with temperatures above freezing most of the time, must present a significant obstacle to many of the continental species.
Guy
I understand exactly what you mean, Guy. I lived in Toulouse for a year and although it was often colder during winter than in the UK, periodically there would be days when the weather did things that would be impossible in Britain. In the mid-January of the year I was there, we had an extraordinary day when the temperature reached 18C in the early afternoon and the banks of the river Garonne were packed with locals eating lunch.
Yet going back to the issue that confuses me; why is it that, for example, QOS Fritillaries can and do successfully overwinter in northern France but hardly ever do so in southern England? There is precious little difference in latitude and climate and ambient/radiant conditions are very similar. In fact, parts of northern France are closer to the Arctic Circle than areas of southern England. Maritime influences are broadly similar too. Given that this species is a strong flier and disperses widely and willingly almost as a matter of routine, I find it hard to reconcile its apparent incapability to put down roots in the south of England when it clearly relishes the conditions in northern France.