Northern Prairie Wildlife Research Center
The gray squirrel is similar in appearance to the fox squirrel but is slightly smaller and lacks the reddish-orange coloration. The head, back, and sides are gray with a brownish tint. The tail is bushy with hairs being buffy at the base, black in the middle, and white at the ends. The fur on gray squirrels can fade during winter months and therefore may appear more reddish in color during these times.
Preferred habitat of the gray squirrel is mature, deciduous forest including trees such as oak, basswood, maple, and hickory. In North Dakota, gray squirrels are found primarily in the eastern one-fourth of North Dakota. Populations have also established themselves in other suitable habitat in the west, including the Killdeer Mountains.
Like the fox squirrel, the gray is active only during daylight hours and eats primarily nuts but will also dine on buds, leaves, flowers, bark, and an occasional insect. They will also hoard nuts by hiding them around their territory for later consumption. An extended breeding season, like seen in fox squirrels, is also exhibited. Males are active during two peak reproductive periods in January-February and in May-June. With a gestation period of 40-45 days, this produces two litters of young per year, one between February and April, and another between late June and August. An average 2-4 young are born in a nest that is usually located within a natural cavity of a mature, dead, or dying tree. Occasionally these squirrels also build leaf nests within tree branches but are less likely to do so than fox squirrels.
Adult grays have a high survival rate for rodents and may regularly live five or six years. Predators of this species include the coyote, red fox, raccoon, long-tailed weasel, and several hawks and owls. The gray squirrel is considered a small game species in North Dakota. Hunting pressure for these squirrels is light to moderate compared to southern states where squirrels are very desirable table fare.