Did you know…black squirrels are really just grey squirrels, except they have darker fur? It’s true.
Black squirrels are what we in the scientific field call a color morph. To be really technical, they are the melanistic phase of the grey squirrel, which means that they have an extra dose of melanin in their make up. It’s essentially the opposite of albinism: albinos have a lack of melanin, which is why they are “colorless.” Melanistic squirrels are considered to be a case of “adaptive melanism,” which means that the ones who were darker were better able to survive (probably because they were more difficult for predators to see), and therefore passed their genes on to their offspring, thus creating whole populations of black squirrels.
Now, there are white grey squirrels, too. Olney, IL is famous for it’s white squirrels – they are even featured on the patches worn by the police department! Several other cities also have white squirrels, but Olney is considered the “White Squirrel Capital of the World.” These squirrels are leucistic, which means they have no pigments at all in their skin (not just a lack of melanin).
Anyway, a black squirrel has been showing up at our birdfeeders off and on for the last couple of weeks. He (she?) stands out because mostly we have fox squirrels, red squirrels and chipmunks at the feeders. Grey squirrels, regardless of color, are not seen all that often, even though they are around. We also have flying squirrels, but they are nocturnal and while it seems like some of us live here at the Dahlem Center, we do in fact go home at night, so we don’t see our night-time visitors.