The Recent Decline of the Black Squirrel Population

The “SquirrelMapper” project, on Zooniverse.org, is a study conducting research on declining levels of black squirrels, which are now rare compared to gray squirrels. Both types of squirrels are color morphs of the same species: Sciurus carolinensis. Black squirrels were more abundant until about 150 years ago, and “SquirrelMapper” is determining the cause of the sudden decline. The project suggests that the changing forests and urbanization of areas could cause the recent cluster of black squirrels in cities and the decline in population in the countryside. This research project tested the null hypothesis that there is no difference between occurrences of black and gray squirrels in various environments. Data were collected by analyzing photos that were submitted from around the world, and the results show gray squirrels are much more prevalent throughout the globe. The results also show the ground as the most-depicted location and that squirrels commonly occur independently