By James Masek, Wildlife Biologist
The scientific name of the Southern flying squirrel (Glaucomys volans) is a combination of Greek and Latin words meaning “flying gray mouse.” This name is only partially correct. While the southern flying squirrel does resemble a gray rat, it is a glider and does not possess the ability to fly.
The Southern flying squirrel is easily distinguished from other squirrels by a flap of loose skin that extends from wrist to ankle – the gliding membrane – large dark eyes, a flattened gray tail, and prominent ears.
The Southern flying squirrels live in hollow trees, deserted woodpecker holes, and in buildings or bird houses. Their nests are made of soft materials like shredded bark, dry leaves, moss, feathers, and fur.
Southern flying squirrels breed twice a year, in January-February and again in June-July. Following a 40-day gestation period, two to seven young are born. The young flying squirrels are born naked and helpless in their nest. Their ears open within two to six days. They develop some fur by seven days old, and their eyes open by 24 to 30 days old. Females care for their young in the nest and nurse them for 65 days. The young become independent by 4 months old and sexually mature at 12 months.
Flying squirrels are not true fliers, but gliders. A loose fold of skin connects the forelimbs to the hind limbs from wrist to ankle and serves as the gliding membrane when their legs are fully extended. They leap from high vantages and spread their arms and legs, stretching the loose skin of the body into an efficient sail. As they approach a landing, they raise their tails to change the course of the glide upwards and extend their limbs to use the skin as a parachute. They are agile in the air, avoiding obstacles like trees and even making 90-180 degree turns. The average glide is 20 to 30 feet, but glides in excess of 100 feet have been documented. Although graceful in flight, they are quite vulnerable on the ground.
Flying squirrels feed on mast from trees such as red and white oak, hickory, and beech. They store food, especially acorns, for winter consumption. They are the only carnivorous members of the squirrel family and readily eat insects, bird eggs, and even carrion.
Southern flying squirrels have very large eyes in order to see well in low light and are active mainly after dark. The most successful predators on flying squirrels are animals that are able to fly, such as hawks and owls, or that can climb well, such as domestic cats, bobcats, raccoons, and climbing snakes.
Southern flying squirrels are often the most common squirrel in hardwood woodlands and suburban areas. However, their nocturnal habits limit interaction with humans.