When I was a lad, there was a little brown butterfly that graced the limestone areas of County Durham that certain butterfly people were determined should be called the northern brown argus, as distinct from the ordinary brown argus, which occurs in the south of Britain where it is warm, calm and dry. Then, as I remember it, someone invented DNA testing and it turned out that the northern brown argus was just a variation of the brown argus. But now, I am rather surprised to find that they, whoever they are, have decided that actually the northern brown argus is indeed a separate species.
This is interesting, or confusing, because on Friday, Mark Stokeld, one of our Saltholme guides, took this photograph by Paddy’s bridge, of a butterfly which then moved off in the wind.
So which one is it ?
I have no idea.
The soft southern brown argus is supposedly at it’s northern limit in south east Yorkshire. And the t-shirt wearing in winter northern brown argus supposedly at it’s southern limit at Castle Eden Dene. The brown argus has two generations a year, the second flying in August. The northern brown argus has only one generation a year flying in June / July.
As we exist in a no man’s land for little brown arguses, then this is a wanderer from either the north or the south. But, the experts in little brown arguses tell us that they do not travel far from where they emerged.
Confused ?
The picture is clear. Either it is a soft southerner who has moved north because of climate change, or, it is a marauding northerner who has got sick of the awful summer we’re having and has decided to head south.
Or maybe, there are more of them than we know ?