Flying with the Greatest of Ease: Gliding Mammals
Southern Flying Squirrel
Southern Flying Squirrel

Southern Flying Squirrel

Glaucomys volans

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This is one of two species of flying squirrel found in Connecticut. Like most gliding mammals, it is active at night and can be found in suburban backyards and city parks. Flying squirrels sleep during the day inside hollow trees, but also like attics and rafters of buildings.

Indian Giant Flying Squirrel
Petaurista philippensis
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This specimen was collected in 1936 in Sri Lanka. There are seven other  species roughly this size in Asia. The Japanese giant flying squirrel can  glide over 525 feet (160 meters), further than any other gliding rodent.

Bats are the only mammals with wings and so are capable of producing thrust and true flight. Mammals that glide instead have a unique adaptation that allows them to ³fly² ‹ a membrane, or patagium, which is a flap of skin between the forelimb and hind limb supported by cartilaginous extensions. By varying the tension of this membrane, the animal can change the speed and direction of its flight.  The patagium is an example of convergent evolution; that is, it evolved multiple times in different groups, resulting in distantly related groups sharing the capability for gliding.

Sugar Glider
Petaurus breviceps
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Marsupial sugar gliders have become popular pets. Unfortunately, because  of this popularity wild sugar gliders are sometimes collected illegally in  New Guinea and Australia.

The earliest known fossil of a gliding mammal dates to more than 125 million years ago. Today there are about 60 different species of mammals capable of sustained gliding. These species are spread among six groups: three marsupials, one dermopteran and two rodent families. Rocky, the squirrel of Rocky and Bullwinkle fame and probably the most well known of these animals, introduced generations of children to gliding mammals.

The marsupial species of gliding mammals include sugar gliders, the greater glider and feather-tailed possums. The flying possums have long flat tails that in some species have feather-like hairs that help the animal use its tail like a rudder.

Colugos, or flying lemurs, from Southeast Asia are members of the order Dermoptera. Dermopterans have a membrane of skin, called a patagium, extending from their bodies to their limbs, which enable them to glide. The colugo has the largest patagium possible for its body size. It extends from its shoulder to its hands,  from its hands to its feet, and from its feet to the tip of its tail. There is even webbing between its toes and fingers.

The two gliding rodent groups are the flying squirrels and the scaly-tailed flying squirrels. There are more  species of flying squirrels than in any of the other  gliding mammal groups. These squirrels use their  fluffy tails like a brake when they land from a glide.


Scaly-tailed flying squirrels are found in central Africa  and are named for the rows of pointed scales on the  underside of their tails.