Flying squirrels are easily distinguished by the "gliding membrane", a flap of loose skin that extends from wrist to ankle. The loose skin along the side of the body is supported by stiff extensions of the wrists and ankles. The soft fur on the back and tail is grey and the belly is white. The tail is flattened. They are 21 to 26 cm in length with a tail measuring 8 to 12 cm in length.
Southern flying squirrels are found in southeastern Canada, the eastern United States, and south as far as Mexico and Honduras. They have a Nearctic distribution.
Southern flying squirrels are found in woodlands. They prefer seed-producing hardwood trees, such as maple, beech, hickory, oak, and poplar. They are also found in forests with mixed hardwood tree and conifer trees.
Not much is known about mating in southern flying squirrels.
Females usually mate twice per year during the warmer months, from February to September. Populations living farther south give birth to their young earlier in the year than do populations living in the northern parts of the range. Females are pregnant for about 40 days and give birth to 1 to 6 young (usually 2 to 3). Young southern flying squirrels are fully grown by one year old.
Young flying squirrels are born naked and helpless in their mother's nest. Their ears open at 2 to 6 days old, they develop some fur by 7 days old, and their eyes open by their 24th or 30th day of life. Females care for their young in the nest and nurse them for 65 days, which is an unusually long time for an animal of this size. The young become independent by 4 months old unless they are born later in the summer, in which case they usually overwinter as a family.
Southern flying squirrels in the wild can live to 5 or 6 years old. In captivity they have been known to live up to 10 years. Most flying squirrels probably die in their first year of life.
Southern flying squirrels are mainly active at night. They are normally solitary or in family groups, but in the winter in the northern parts of their range they come together in communal nests of 10 to 20 animals. This is probably to keep warm, they huddle and snuggle in large nests. Females are territorial during the breeding season and keep other females out of their area. Flying squirrels live in hollow trees, deserted woodpecker holes, and in buildings and bird boxes. Nests are made of soft materials like shredded bark, dry leaves, moss, feathers and fur.
Flying squirrels do not actually fly, they can only glide. But they can glide quite long distances. They leap from high points, such as the tops of trees, poles, and cliffs, and spread the arms and legs, stretching the loose skin of the body into an efficient sail. As they approach a landing, they raise the tail to change the course of the glide upwards and extend the limbs to use the skin as a parachute. When they land, they quickly move to the other side of the tree to avoid predators that may have detected and followed them during the glide. They are agile in the air, avoiding obstacles like trees and even making sharp turns. From a height of 18 meters they can glide about 50 meters; the maximum glide is about 80 meters.
Not much is known about communication in southern flying squirrels. They have excellent senses of smell, vision, hearing, and touch. They have large eyes which help them to see at night and whiskers on their chin, cheeks, and ankles that they use to help them in detecting their way along tree trunks at night.
Southern flying squirrels are omnivores and eat a wide range of foods, including nuts, acorns, seeds, berries, fruit, moths, junebugs, leaf buds, bark, eggs and young birds, young mice, insects carrion, and fungus. They are especially fond of hickory nuts and acorns; one sure sign of the presence of this species is piles of gnawed hickory nuts at the base of large hickory trees. They will store food for winter use.
Flying squirrels avoid predators by being nocturnal and by being fast and agile in the trees and during their glides. They are alert for predators constantly. The most successful predators on flying squirrels are able to fly, such as hawks and owls, or can climb well, such as domestic cats, bobcats, weasels, raccoons, and climbing snakes.
Flying squirrels disperse the seeds of hardwood trees and the spores of fungi.
Flying squirrels are sometimes pests when they make nests in houses.
Flying squirrels play important ecosystem roles in hardwood forests. They are also sometimes kept as pets.
Some populations of southern flying squirrel in Central America are rare and may be endangered. Throughout most of their range, though, flying squirrels are common.
Southern flying squirrels are often the most common squirrel in hardwood woodlands and suburban areas. Because they are nocturnal and seldom seen, most people don't recognize that they live with flying squirrels.
Baker, R. H. 1983. Michigan Mammals. Michigan State University Press.
Forsyth, A., 1985. Mammals of the Canadian Wild. Camden House Publishing Ltd.: Camden East, Ontario, 351 pp.
Nowak, R. N., 1991. Walker's Mammals of the World. The Johns Hopkins University Press: Baltimore, MD, 1629 pp.