Flying Squirrel Biology
Flying squirrels have soft, gray-brown fur on the back and sides, with white under parts, a flattened tail and large, dark eyes for night vision. The northern flying squirrel is slightly darker and redder than the southern flying squirrel. The northern with a length of 9.8 to 11.5 inches and weight of 2 to 4.4 ounces is larger then the Southern flying squirrel with a length of 8 to 10 inches and weight of 1.8 to 2.5 ounces. The loose folds of skin between the front and hind legs of these squirrels enables them to “fly;” they actually glide through the air on the stretched surface of this loose skin.
The southern flying squirrel is found from southern Canada south to southern Florida, west to Minnesota and eastern Texas. The northern flying squirrel is found from southeastern Alaska and northern Canada south to Tennessee and west to the Pacific coast. Southern flying squirrels are very common in New Jersey, whereas it is rare to find northern flying squirrels in our area.
Mating occurs in late winter, and after a 40-day gestation period, an average of three to four young are born. A second breeding period occurs in the summer. The young are born blind and helpless but develop more quickly than other squirrels. By six weeks of age, they are able to forage on their own. Tree cavities, birdhouses and building structures may be used as nesting sites. The nest may be lined with shredded bark, leaves, moss, feathers, and other materials.
Depending on the air current, flying squirrels may glide 150 feet or more from a height of 60 feet. They can turn easily at right angles while gliding and control the direction of their glide by tensing and turning their legs and body and flapping their tail. As a flying squirrel approaches its landing, the squirrel flips its tail up and holds its body back to slow the glide down, giving the squirrel ample time to position its feet for grasping the tree trunk. Flying squirrels usually land face up and often run up the tree immediately after landing.
Flying squirrels are active year-round, are highly sociable, and will feed and den together, especially during periods of harsh weather. There are even reports of flying squirrels denning with other animals, including screech owls and bats.
The flying squirrel is a nocturnal creature that prefers to live in colonies. During the winter months they will seek shelter and take up residence in homes and, they will bring their friends. It is not uncommon to have 20 flyers living in an attic! Being that they are nocturnal, or active at night, they start their activities at sundown storing food inside your home. They are quite noisy at three or four in the morning. Because of their small size they may make noise in walls throughout your home, as well as your attic. A southern flying squirrel can gain access to your attic and walls from roof vents and construction gaps to improperly installed chimney caps. They only require a 1 inch in diameter gap to gain access into your home.
Flying squirrels are members of the rodent family. Like all rodents, to keep their teeth sharp they must chew. Homes with flyer colonies often have chewed electrical wires which, if gone unnoticed, can a fire hazard. These animals will set up a “litter box” that can produce stains and smells that are unbearable. The most common complaint from homeowners stems from the night noise and the noise in the walls these critters make. It is hard to sleep when you have flyers storing acorns in your home every night.