By Jena Donnell
Photograph by Ken Thomas
The Southern flying squirrel, Glaucomys volans, is one of the smallest Oklahoma squirrels, measuring only eight to 10 inches long including a three to four inch tail.
Although primarily gray with a cream-colored stomach, there are reports of reddish brown flying squirrels. This small rodent weighs only three ounces at adulthood-slightly more than a regulation tennis ball. The only nocturnal member of the squirrel family, flying squirrels have large eyes that help them navigate in the dark.
Southern flying squirrels are found in deciduous forests, primarily in stands of oak, hickory or walnut in the eastern half of Oklahoma. Even so, they have been recorded as far west as Comanche County in southwestern Oklahoma.
These squirrels rely on fruit or nut producing trees for food and nesting habitat. Although nuts make up the bulk of the flying squirrels diet, they are one of the most omnivorous of squirrels-feeding on everything from flower blossoms to bird eggs.
Another distinction between the flying squirrel and other tree squirrels is the feeding pattern. Flying squirrels cut a uniform circle on the side or end of each nut, leaving the shell intact. Other tree squirrels crush the shell to reach the meat.
Despite the name, the Southern flying squirrel doesn't actually fly-it glides.
Flying requires an unassisted gain in altitude, while gliding can be described as descending with style. Regardless of the terminology, watching this squirrel travel from tree to tree is quite a treat!
These arboreal rodents are able to gracefully travel long distances-up to 200 feet-by way of two adaptations.
The first is the thin layer of fur covered skin, or patagium, extending from the fore feet to the back feet. When stretched tight, this patagium acts as an umbrella, allowing the squirrel to glide through the air. The second adaptation is the flattened tail. Almost half of the total body length, the tail acts as a stabilizer and also helps when balancing on small limbs.
Southern flying squirrels are cavity nesters, using their nest throughout the year. These squirrels often use cavities originally excavated by woodpeckers, sometimes even causing woodpeckers to abandon the nest. Entrance holes to the squirrel nests are generally larger than one inch in diameter and the cavity is lined with bark and leaves.
These rodents typically breed twice a year-once in late winter, and again in mid to late summer. The litter ranges from one to six, but often contains only two to three young, weighing only a quarter of an ounce each at birth. The nestlings are able to glide eight weeks later.
Because of their nocturnal lifestyle, not much is known about the Southern flying squirrel's distribution or conservation status. While recent research has shown that these squirrels have a larger Oklahoma distribution than previously known, reliable population estimates are unavailable at this time.
Predators of the Southern flying squirrel include birds of prey and snakes, but the most common predator seems to be domestic cats.
The next time you go camping or sightseeing in Oklahoma's eastern deciduous forest, be on the lookout for the Southern flying squirrel.
Written by Jena Donnell, who is a quail habitat biologist with the Oklahoma Department of Wildlife Conservation.