Description

Northern flying squirrels range from about 7 to 10 inches in length, not including the tail, which is generally about 80% as long as the body. They have silky gray and cinnamon brown fur, with white-tipped and gray-based belly hairs. Both sexes are similar in size and coloration.

The most distinguishing feature of the flying squirrel is a web of furred skin along both sides of the body extending from the foreleg to the hindleg and ending on the tail.

Distribution and Habitat

The northern flying squirrel ranges from the treeline in Alaska and Canada southward to northern California and Colorado, and from central Michigan and Wisconsin into northern North Carolina and Tennessee. It is most commonly found in areas dominated by conifers, but are also found in deciduous and mixed forests.

Habits and Behaviors

Strictly nocturnal, northern flying squirrels are active for about two hours beginning an hour after sunset, and again for about one-and-a-half to two hours before sunrise. They rest by day in hollows in trees and will also use roof spaces, outbuildings and bird nesting boxes.

Female northern flying squirrels are territorial, but males are not. Groups of up eight adults and juveniles may share a single nest, especially during the winter.

Diet

Like most squirrels, the northern flying squirrel feeds on nuts, acorns, fungi, and lichens, supplemented by fruits, buds, sap, and the occasional insect and bird egg. Food is often hoarded in order to ensure a steady supply during the winter months.

Reproduction

Breeding takes place between March and May, with one to six young born after a gestation period of 37 to 42 days. Young are weaned after about two months, and are able to live on their own after about three months. Sexual maturity is reached at about one year of age.

Flight Abilities

One could say that flying squirrels do not truly fly because they do not have wings like birds or bats, and such a statement would be somewhat true. However, to say that a flying squirrel simply glides from one tree to another would actually be quite far from the truth. In fact, the only real difference between birds/bats and flying squirrels is that the former are capable of powered flight, whereas the latter engage in controlled flight without wing beats.

Before becoming airborne a flying squirrel leans its head first to one side then to the other, getting a "fix" on the distance and direction it must travel to its desired landing spot. After determining where it wishes to land, the squirrel leans forward, pushes with its hind legs and spreads all four legs at right angles to the body so the flying membranes form a near-perfect square. In flight, the squirrel uses its tail as a balance and a rudder to help keep it on course. In addition, by dropping the legs of one side, to give added lift to the membrane on the other side, the squirrel can bank or turn sharply. It can also dive steeply and use the speed to rise steeply at the end of the dive.

On landing, the squirrel immediately races around to the other side of the tree, a precaution against attack from a predator while still recovering from the landing.

Although most glides are simple, from one tree to another in a direct line, flying squirrels have been seen to make right-angled turns, lateral loops, spiral ascents and other aerobatics. They have even been seen to change their minds in mid-flight, turn completely around and land again on the exact spot from which they had just taken off.

Young flying squirrels make their first short flights, under the close supervision of their mothers, at about one month of age.

Scientific Classification

Phylum Chordata
Subphylum Vertebrata
Class Mammalia
Order Rodentia
Suborder Sciurognathi
Family Sciuridae
Subfamily Pteromyinae
Genus and Species Glaucomys sabrinus

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