Eastern gray squirrel (Sciurus carolinensis) color morphs do not differ in aggressiveness

Abstract

Eastern gray squirrels (Sciurus carolinensis) exhibit a variety of color morphs, including black. In the USA and UK, a common folk belief is that black squirrels are more aggressive than squirrels of other colors. We tested the biological basis of that belief using data from the 2018 Central Park squirrel census. Contrary to the belief, black squirrels do not chase other squirrels more often than do conspecifics of other colors. Black and non-black squirrels were equally likely to approach people for food and to display indifference to human presence, but black squirrels were more likely than non-black squirrels to flee from people. Although other research has found that aggression among squirrels increases when they live in higher population densities, black squirrels were no more aggressive than non-black squirrels despite the fact that they were sighted in parts of Central Park with higher squirrel population densities than other locations.