A certain type of squirrel is surprisingly common in some areas. These squirrels have a mutation that affects their coat color, resulting in a dark appearance. This mutation is linked to a specific gene and can be found in eastern gray squirrels.

The mutation is not unique to a particular species, but rather a variation of an existing one. It is more prevalent in certain regions, with high numbers found near the Great Lakes.

Further information about this phenomenon is available, including videos and studies that shed more light on the subject.