Some of the Eastern Gray Squirrels (Sciurus carolinensis) at my local marshland park are not gray—they are black. Some of them are pure black, while others, like this one that I photographed yesterday, seem to be a mixture of gray and black. What’s going on here?
According to Wikipedia, black squirrels are a “melanistic subgroup” of the Eastern Gray Squirrel caused by the presence of mutant pigment genes. If there are two mutant genes present, the squirrels will be jet black, but they will be brownish-black if only one such gene is present.
In a fascinating bit of historical trivia, the black subgroup seems to have been predominant throughout North America prior to the arrival of Europeans in the 16th century, as its dark color helped them hide in old growth forests which tended to be very dense and shaded. As time passed, hunting and deforestation led to biological advantages for gray-colored individuals.
Squirrels seems to be very active right recently, preparing for the colder days to come. They always seem to be in a big hurry and I was happy to be able to photograph this one as it took a short break from its frenetic activity.
© Michael Q. Powell. All rights reserved.
Mike Powell 