Interesting how much variation there is between polish, czech and dutch populations of these squirrels. The ones in western Czech republic are almost black, where the ones in the Netherlands are much redder and don't have such a large ear tuft.
Black or rather dark brown squirrels are are characteristic for mountainous areas, so in southern Poland are quite common. For example, in my city about half of the population is dark brown and another half red.
The same percentage is in central Bohemia. 50% are red and 50% are dark coloured. This is based on my own observations as well as on statistics from a local squirrel rescue centre.
