The northern flying squirrel is considered to be among the most aerodynamically sophisticated of all gliding mammals (3), able to travel anywhere between 3 and 45 metres in a single glide (4). It uses this skill to travel between trees to feed on a variety of fungi and lichens in particular, although insects, nuts, buds, seeds and fruits are also eaten. The northern flying squirrel also spends a considerable amount of time feeding on the ground (1).
The northern flying squirrel maintains one of several dens throughout the year. In winter, this is often a cavity in a conifer tree, and, as this species does not hibernate, several individuals may share a nest to keep warm (5). During breeding, which occurs between February and July (1), the female northern flying squirrel typically selects a den in lower parts of a tree. This species may shift between different den sites, even when rearing young (5).
One or two litters of 2 to 6 young are born each season, after a gestation period of 37 to 42 days. The young are weaned at around 2 months and reach sexual maturity at 6 to 12 months (1).