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Editor's Note: The following article is part of a series of scientific reports authored by members of the Arkansas State University faculty and published periodically by The Jonesboro Sun.

By Aldemaro Romero

and Thomas S. Risch

If there is a group of misunderstood creatures, it is the flying squirrels.

To begin with, flying squirrels do not fly. Unlike bats and birds that power themselves by beating their forelegs, flying squirrels glide. Once they launch themselves, they are capable of steering their flight trajectory by adjusting the tightness of the membrane that extends around their forelegs.

Unlike the image given by the cartoons of Rocky and his friends of "The Rocky and Bullwinkle Show," they do not use their tails to glide. The tail is utilized as a stabilizer in flight much like the tail of a kite.

The key for these gliding abilities resides in the furry skin that extends along both sides of the body from the wrist to the ankle and, in some species, all the way to the tail. When extended, this fold of skin acts as a parachute.

When the animal is not gliding, the flaps are folded.

To glide, the squirrels jump from a high point in a tree and land at a point lower than their starting point; the giant flying squirrel is capable of gliding as far as 400 yards.

As spectacular as these flights are, they are rarely seen because these species are nocturnal. Flying squirrels are thought to glide because of the patchy nature of their food supply. The nuts they eat, such as acorns and hickories, are found in high numbers on certain trees spread out through the forest. By gliding, the squirrels are able to move from tree to tree quickly while avoiding predators.

There are 36 species of flying squirrels in the world (mostly in Asia) and two species in North America, one of which, the southern species, is found in forested areas of Arkansas. It is about 10 inches long, including the tail. The largest of the species is the woolly flying squirrel that lives in southern Asia and can reach four feet in length.

One of us (Risch) has been studying the reproduction and feeding behavior of southern flying squirrels for the past 13 years. These squirrels nest in tree holes and have an extended breeding season when nuts are abundant. The first pups are born in the early fall when the hickories begin to ripen.

If it is a good year for nut production, most females will have two or even three litters of pups a year, beginning reproduction in late August and ending in May. A typical family size is three young, and the largest litters of five or more pups are born during the fall when the nuts they depend on are the most abundant.

Risch also injected squirrels with microchips. The chips are read by an antenna that is placed around the entrance of a box baited with pecans. In this way the chip is read, and information is sent to a hand-held computer at the base of the tree.

The computer stores the information, which includes which squirrel is present, when it feeds, and for how long. During the breeding season females with pups are the first to arrive at the boxes each night. Adult males, who are likely looking for females, are the last to arrive to the feeding boxes.

During the summer these differences in feeding behavior do not occur; males and females arrive at essentially the same time.

In addition to needing the extra food to produce milk for their young, the females are probably defending the food from the males. Unlike most mammals, females are about 15 percent larger than males in this species, allowing them to fight off males around food sources.

Although the nut crop, also know as hard mast, is one of their most important food items, they actually have a varied diet that includes wild grapes, bird eggs and insects. But the nuts are vital during the breeding season.

As many local residents are aware, the past two years have been poor for acorn production. The failure of the hard-mast crop has affected the squirrels whose numbers have dropped considerably in and around the Jonesboro area. But their high reproductive rate ensures that their numbers will rebound as soon as favorable conditions for hard mast return.

For more information contact the ASU Department of Biological Sciences at biology@astate.edu.

Romero is chairman and professor and Risch is assistant professor in the Department of Biological Sciences at Arkansas State University.