Flying squirrel

From Freepedia

Flying squirrels
Fossil Range: Early Oligocene - Recent

Image:Glaucomys sabrinus.jpg
Northern Flying Squirrel (Glaucomys sabrinus)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Mammalia
Order:	Rodentia
Family:	Sciuridae
Subfamily:	Petauristinae

Genera

See Genera.

The Petauristinae (also called Pteromyinae) is a subfamily of squirrel (family Sciuridae). They are usually called flying squirrels. There are 36 species in this subfamily, the largest of which is the Woolly Flying Squirrel (Eupetaurus cinereus). The 2 species of the genus Glaucomys (Glaucomys sabrinus and Glaucomys volans) are native to North America, and it is these that are most often meant when the name "flying squirrel" is used in English.

Flying squirrels do not fly in the same sense as birds or bats - they do not employ powered flight. Rather, they glide: once they have launched themselves into the air, they have no means of forward propulsion. They are true gliders: that is, unlike a human-made sailplane, they do not use upcurrents in the air to soar, so they will lose height during a glide. However, they can steer themselves very adroitly while in a glide. They do not steer with their tails, as is commonly but erroneously reported. Steering is accomplished by adjusting tautness of the patagium and positioning of the forelegs. The tail acts as a stabilizer in flight, much like the tail of a kite, and as an adjunct aerofoil when "braking" prior to landing on a tree trunk.

The flying squirrel has been kept as a domestic pet since the American colonial era. Noted for their tight bond with their owner, the flying squirrel is a very small, low-maintenance creature. Though their lifespan is only about five years in the wild, flying squirrels often live between 10 and 15 years in captivity. This difference in lifespan is due to the natural calcium defficiency of the flying squirrel. In the wild, the animal does not naturally supplement its diet with calcium and thus develops rickets and dies fairly young. In captivity, a small amount of calcium supplement can be added to their diet, prolonging their life by a factor of between two and three.