Sighting a black squirrel for the first time is exciting. Despite its appearance, a black squirrel in Massachusetts is actually an eastern gray squirrel in disguise.
Color Change Causes
The color variations are the result of a genetic mutation that causes excessive pigmentation. This phenomenon occurs in many species, and the individuals are called "melanistic," which refers to melanin, a chemical of pigmentation. The process of natural selection determines whether the black morph will be successful in a particular region.
Although occasional melanistic gray squirrels are found throughout the gray squirrel's entire range (approximately the eastern half of the United States), the incidence seems to be greater in the North. Massachusetts has established populations located near Springfield and scattered throughout the suburban Boston area.
The well-established colony of black-phase gray squirrels at the Stanley Park preserve in Westfield, Massachusetts, is thought to have descended from a pair of black-phase gray squirrels that were brought there from Michigan and released in 1948. It is likely that the melanistic squirrels seen in the Amherst, Southwick, and Springfield areas are related to the Westfield squirrels.
The rare squirrel that appears all white is also technically a gray squirrel, but with a reduced amount of dark pigment. These squirrels are considered leucistic or partially albinistic. In order to be a true albino, the squirrel would also have pink eyes.
Most New Englanders are familiar with the ever-present gray squirrel. An extremely adaptable species, squirrels are at home everywhere from midtown parks to oak forests. Learn More