Flying squirrels are related to tree squirrels but formed their own phyla, Glaucomys, [from Greek, silver-gray (glaukos) mouse (mys)] 18 to 20 million years ago. There are some 44 species found around the world, two of which, G. sabrinus (northern) and G. volans (southern) are in North America. Mating occurs over February and March with a gestation period of 40 days. A litter of 4-6 young is produced in a tree cavity or abandoned tree squirrel leaf nest. After 8 weeks the young attempt their first glide. Their life span is 5-6 years.
Bahlman, K.S, S.M.Swartz, D.K. Riskin. 2013.
Glide performance and aerodynamics of non-equilibrium glides in northern flying squirrels (Glaucomys sabrinus).
Rosenberg, D.K., J.R. Waters, K.J. Martin, R.G. Anthony, C.J. Zabe
The Northern flying squirrel in the Pacific Northwest: Implications for management of the Greater Fundy ecosystem.
Wisconsin Department of Natural Resources – Bureau of Endangered Resources
Northern Flying Squirrel (Glaucomys sabrinus) Species Guidance
Scheibe, J.S., W.P. Smith, J. Bassham, D. Magness
Locomotor performance and cost of transport in the northern flying squirrel Glaucomys sabrinus