Listed as a species of special concern, the southern flying squirrel requires mature trees with a classic understory that includes dead trees and fallen rotting logs for nesting and a food source. The rotting logs provide structure for fungus growth that is an important food source. Mostly found in upland eastern deciduous forests although they can be found in floodplain timber. They are almost completely dependent upon oak/hickory forests.
The flying squirrels are the only nocturnal tree squirrels. The flying squirrel does not truly fly, but glides through the air, up to 80 yards (meters) or more, from the top of one tree down to the trunk of another. It flies with its legs outstretched and the fold of skin (patagium) between foreleg and hind leg acting as a combination parachute and sail (or glider wing). While gliding, it can turn or change its angle of descent. Agile and extremely surefooted aloft, it is relatively clumsy on the ground.
The most carnivorous of the tree squirrels, the Southern Flying Squirrel feeds on nuts, acorns, seeds, berries, fungi, lichens, birds and their nestlings and eggs, some insects, and sometimes other vertebrates, including carrion. Woodpecker holes are favored nest sites, but the Southern Flying Squirrel may build a summer nest of leaves, twigs, and bark that is similar to that of gray or fox squirrels. In winter, several individuals may den together in one tree hole, as their combined body heat brings up the den temperature; as many as 50 individuals have been found in one nest in winter.
The Southern Flying Squirrel mates in early spring. The female is receptive for just one day. She usually mates with the dominant male, and often a subordinate as well. At about four weeks of age the young resemble adults; at five weeks, they exit the nest to take solid food. Females of this species defend their young vigorously, and will move them to another nest if danger threatens. Predators include owls and many mammals, but the house cat is the most dangerous.
Flying squirrel populations in Iowa are unknown, but the loss of mature mast producing trees in stands of timber and "cleaning up timber" by removing fallen and rotting logs can impact local populations.
Maintain older wood lots to improve flying squirrel populations. Reduce the amount of harvest in timber with known populations. Leave rotting material and maintain snag trees. Large areas can have a larger percent of timber harvest while smaller areas must have a smaller percent of timber harvest. Plant new trees along the periphery of small stands of timber that include high amounts of oak and hickory species. Construct and place artificial nest boxes (see diagram).
Southern Flying Squirrel Nest Box - Instructions