Glaucomys volans
southern flying squirrel

Glaucomys volans is found in southeastern Canada, the eastern United States, and south as far as Mexico and Honduras.

Southern flying squirrels are found in woodlands. They seem to prefer seed-producing hardwoods, particularly maple, beech, hickory, oak, and poplar. They are also found in mixed conifer/deciduous forests.

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 cartilaginous spurs on the wrists and ankles. The soft fur on the back and tail is grey with varying amounts of grey tinge; the belly is white. The tail is dorso-ventrally flattened. The eyes are very large, probably related to the nocturnal habits and the visual requirements of gliding. Total length is 21.1 to 25.7 cm and tail length is 7.9 to 12 cm.

Little is known about the mating system in southern flying squirrels. Males and females do not associate much beyond breeding.

Not much is known about mating in southern flying squirrels.

Females are polyestrous and typically mate twice per year. Births thus have two peaks, from February to May and from July to September. There is, however, some geographic variation in the timing of births. (In Michigan, they court and breed in winter and early spring.) The gestation period is 40 days. Litters can range from one to six young, though two or three is most common. The young are weaned at 65 days (an unusually long time for an animal this small) and are independent at 120 days. Maturity is usually attained at twelve months, though ages as young as nine months have been reported.

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.

Activity is primarily nocturnal. Flying squirrels are often seen in pairs, and can be gregarious. During winter, groups of 10 to 20 individuals are sometimes found in dens in hollow trees. Females have been reported to be territorial and to defend nest sites during the mating season. 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 are not true fliers but gliders. They leap from high vantages 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. Upon landing, 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 90 turns. From a height of 18 meters they can glide about 50 meters; maximum glide is about 80 meters.

Home ranges in both sexes range in size from about .5 to about 1.5 hectares. Male ranges overlap; female ranges do not overlap with each other or those of males.

Southern flying squirrels have very large eyes in order to see well in low light. They have keen senses of smell, touch, vision, and hearing. They probably communicate about reproductive condition through chemical cues. Vibrissae on the cheeks, chin, and ankles help them in navigating at night. They are relatively quiet but may use some vocalizations in social communication.

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 consume large numbers of the fruiting bodies of subterranean fungi, dispersing the spores in their feces. The mycelia of these fungi form close associations with the roots of many species of trees and are believed to be essential for tree growth and maintenance. They also disperse the seeds of hardwood trees.

Flying squirrels play important ecosystem roles in hardwood forests. They are also sometimes kept as pets.

Flying squirrels are sometimes pests when they make nests in houses.

Some subspecies in Central America are rare and may be endangered.

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.