"Most of the Southern Flying Squirrel's range is east of the Mississippi River, but it occurs west of the river in central Texas, and as far south as Honduras, in Central America. Like the Northern Flying Squirrel, it has a gliding membrane (patagium) and a flattened tail. Flying squirrels are nocturnal and are much smaller than most tree squirrels, which are diurnal. Although primarily associated with hardwoods, especially oaks and hickories, Southern Flying Squirrels inhabit forests of diverse types, and even live in cities and suburbs. A natural cavity or old woodpecker hole in a live or dead tree is the typical nest site. Where the ranges of the two species of flying squirrels overlap, it appears the Southern Flying Squirrel may out-compete its larger relative."

Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account