This black phase grey squirrel was sitting quietly in the old woods, catching the same sun's rays as the grey squirrel in the next photo. They look quite different, but are in fact the same species. The further south one goes, the less these black squirrels are found, until they just stop appearing at all. Thus, they appear to be a mainly northerly colour phase. Speculation is that the darker colour absorbs and retains heat better in the winter. Whether this is so or not, there are definitely more black phase greys than grey greys here.