|Glaucomys sabrinus (Northern Flying Squirrel)|
Size: Total Length: 10.24 in. (260 mm.). Tail Length: 8.19 in. (208 mm.). Weight: 2-3 oz. (56.7-85.05 g.) 
Description: The Northern Flying Squirrel has dense fur, olive-brown above and white below.
It also has large brown eyes. Its tail is uniformly gray with a dark tip.The tail is also flat for aerial control. The Northern Flying Squirrel has a membrane, called a patagium, which stretches from the front to the hind limbs.
Similar Species: The Northern Flying Squirrel is similar in appearance to the Southern Flying Squirrel, but larger and more robust. The Southern Flying Squirrel has a tail that is paler below and has a darker tip than The Northern Flying Squirrel.
Range: Continuous across North America through central Canada.
Habitat: Northern Flying Squirrels inhabit cool and moist forests near swamps or streams. Mixed coniferous-deciduous forests are ideal habitats for the species. In addition, they can be found to nest in tree hollows or leaf nests.
Activity: They have a nocturnal activity pattern in the late summer, leaving the nest shortly after sundown and returning within two hours. They do not hibernate, remaining active during the winter months.
Reproduction: Mates in late March through May. Gestation period of 37-42 days. Typical litter size of 2-4 (2-3 litters per year). Newborns weigh .18 oz. (5-6 g.) and are 2.76 in. (70mm) in length. Weaned at 2 months.
Lifespan: 4 years in the wild. 13 years in captivity.
Notes: The Northern Flying Squirrel has a long tail, up to 80% of its body length. It has no evident sexual dimorphism. Common predators include Barn Owls (Tylo alba), Great Horned Owls (Bubo virginianus), Red-tailed Hawks (Butao jamaicensis), and House Cats (Felis catus). Female Northern Flying Squirrels raise the young, with no help from male. Northern Flying Squirrels are social and often share nests during the winter. The Northern Flying Squirrel actually does not fly; it glides with glide lengths averages of 16.6 ft. (19.7 m.). They also help disperse conifer seeds. The Northern Flying Squirrel is usually clumsy on the ground and will occasionally get its patagium tangled in barbed wire and die.
- Wells-Gosling, Heaney, N., L.R. (1984), Glaucomys sabrinus, pp. 1–8
- Minnesota Department of Natural Resources (2012), Glaucomys sabrinus
- Smithsonian National Museum of Natural History (2012), Glaucomys sabrinus
- Riebe, j. (2004), Glaucomys sabrinus
- Malamuth, Mulheisen, E., M. (1999)