The flying squirrels, scientifically known as Pteromyini or Petauristini, are a tribe of squirrel (family Sciuridae). There are 43 species in this tribe, 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. It is these that are commonly meant when the name “flying squirrel” is used in English.
The term “flying” is somewhat of an inappropriate, since flying squirrels are actually gliders incapable of true flight. This animal achieves gliding by launching off the tops of trees and extending flaps of skin stretched from arms to legs. Once they have launched themselves into the air they are highly maneuverable while in flight. Steering is accomplished by adjusting tautness of the skin, largely controlled by a small cartilaginous wrist bone. The tail acts as a stabilizer in flight, much like the tail of a kite. It is used when “braking” prior to landing on a tree trunk. When the tail has been severed from a flying squirrel it will not glide. It will fall in a pattern more similar to a leaf.
Flying squirrels travel through forests by gliding between trees. The distance traveled in one glide can range anywhere between 32.80 to 142.17 yards (30 and 130 m). They travel quite fast, usually gliding at about 16.4 yards (15 meters) per second. To get this speed, they must dive quite steeply at first. Then they level out to around 12 degrees to the horizontal. They lose a lot of elevation during the steep part of the glide. The trees that the squirrels glide between must be relatively tall 22 yards (about 20 meters) for the gliding to be an effective way to travel.
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 these creatures being important prey animals. Predators include arboreal snakes, raccoons, nocturnal owls, marten, fisher, coyote and the domestic house cat.