|Size:||Length: 10 to 14 inches (25 to 36 cm)|
|Weight:||7.5 ounces (213 g)|
|Diet:||Fungi, nuts, seeds, leaves, berries, fruit, buds, bark, maple sap, acorns, insects and bird eggs|
|Distribution:||Alaska, Canada and northern U.S.A.|
|Young:||2 to 6 young, once per year|
|Animal Predators:||Hawks, owls, martens, foxes, bobcats, lynxes, weasels, wolves and domestic cats|
|IUCN Status:||No special status|
|Terms:||No special terms|
|Lifespan:||3 to 6 years in the wild and up to 13 years in captivity|
<![if !supportLists]>· <![endif]>Northern and southern flying squirrels are the only nocturnal tree squirrels.
<![if !supportLists]>· <![endif]>Flying squirrels are rarely seen because of their nocturnal habits.
<![if !supportLists]>· <![endif]>Its scientific name means grey mouse (glaucomys), and river nymph (sabrinus).
<![if !supportLists]>· <![endif]>Although northern flying squirrels are larger, in regions where they overlap, southern flying squirrels tend to be the dominant ones.
Flying squirrels are dark brown in colour with a white belly. Flying squirrels do not actually fly, but they can glide up to 80 yards (90 m). A thin fold of skin stretching from their forelegs to their hind legs opens like a parachute. They leap from a branch, holding their arms and legs akimbo and glide to another branch or to the ground, landing upright with their hind legs touching first. These squirrels have a summer and a winter coat, and moult twice a year.
<![if !supportEmptyParas]>Their preferred habitats are heavily wooded areas that contain trees such as cedars, spruce, hemlock or birch. Flying squirrels den in hollow trees or abandoned woodpecker holes. In the summer, they sometimes live in leaf-lined nests in trees, but will move to a den for the winter.
Northern flying squirrels tend to mainly eat fungi, however, they also eat nuts, seeds, leaves, berries, fruit, buds, bark, maple sap and acorns, the occasional insect, and bird eggs. They do not eat walnuts because the outer hard shell is too hard for the squirrel to break open.
Mating season is early spring, resulting in a litter of two to six offspring. Males and females sometimes stay together in pairs until shortly before the birth, at which point the male leaves and the female cares for her young alone. The female is very devoted to her young, seldom leaving them. The babies are tiny, each one weighing less than a quarter-ounce (7 g). They are weaned at six to eight weeks and begin gliding soon after.
While female squirrels do not allow other females within their territories, males’ territories will overlap those of other males. When the shortening of the daylight signifies the approach of winter, these squirrels busily gather nuts and store them in tree cracks or crevices in the ground. They are active all night long in this pursuit and can store several hundred nuts in one night. They may share their nest with other squirrels of either gender, and in the winter, form groups of up to 50 for warmth. Because of the extra flap of skin and fur they carry, they are extremely slow runners and if a predator is nearby while the squirrel is on the ground and not near a tree, they will hide rather than try to run to safety.
Two species of northern flying squirrels (the Carolina northern flying squirrel and the Virginia northern flying squirrel) are considered endangered by the United States Fish and Wildlife Service.