Description This little mutant squirrel has become a daily visitor at the feeders here, and for some reason keeps the grey squirrels at bay! This squirrel is an offspring with 1 copy of the mutant pigment gene, therefore showing brown throughout its coat amid the jet black.Photographed in Spring Glen, New York, USAThe black squirrel is a melanistic subgroup of the eastern grey squirrel.As a melanistic variety of the eastern grey squirrel, individual black squirrels can exist wherever grey squirrels live. Grey mating pairs can not produce black offspring. Grey squirrels have 2 copies of a normal pigment gene and black squirrels have either 1 or 2 copies of a mutant pigment gene. If a black squirrel has 2 copies of the mutant gene it will be jet black. If it has 1 copy of a mutant gene and 1 normal gene it will be brown-black. In areas with high concentrations of black squirrels, mixed litters are common. The black subgroup seems to have been dominant throughout North America prior to the arrival of Europeans in the 16th century, since their dark color helped them hide in virgin forests which tended to be very dense and shaded. As time passed, hunting and deforestation led to biological advantages for grey colored individuals. Today, the black subgroup is particularly abundant in the northern part of the eastern grey squirrel's range. This is likely due to the significantly increased cold tolerance of black squirrels which lose less heat than grey squirrel. Black squirrels also enjoy concealment advantages in denser northern forests.