Eastern Gray Squirrels, Sciurus carolinensis, are some of the most visible and well-known urban animals in the Northeastern United States. Prior to European settlement of the region, the black morph of S. carolinensis (“melanistic”) was much more abundant. Scientists have hypothesized that the dark pelt was advantageous in the old growth forests that used to cover the region. … Continue reading Natural Selection Favors Black Morph of Eastern Gray Squirrel in Cities