He is a night owl; I am an early bird. My early morning wanderings, complete with tales of the wildlife encountered, are eagerly showered upon this old friend.
He in turn regales me with his own tales of the nightlife among the wild things in his wooded backyard. Among my favorites are his tales of southern flying squirrels that have entertained him often, with their gliding antics, as they sail in to munch at his bird feeders. These critters swoop in so quickly, that most often they just seem to materialize as Keith watches.
Although these squirrels are found throughout the deciduous forests of eastern North America, from southern Ontario to the Gulf Coast, few people ever get a glimpse of one. The reason is that they are nocturnal — creatures of the night.
Other gliding mammals in other parts of the world also tend to be nocturnal. A possible explanation for this tendency may be that gliding in daylight could more easily attract the attention of hawks and other predators that hunt by vision.
Flying squirrels are much smaller than gray squirrels, measuring 10 inches in length including the 3- to 4-inch tail, and weighing less than four ounces. Their upper body and tail are covered with long, silky-soft, gray-brown fur. Their underside is creamy white, and their large eyes, especially adapted for nighttime, are ringed with black.
Though these squirrels do not fly, as the name implies, they can glide for considerable distances. A fur-covered membrane, edged in black, joins their hind and forelimbs. As these flying squirrels leap from high in trees, spreading wide their fore and back legs, the membrane works much like a sail as they glide to their intended landing site.
They have a broad, flat tail specially tailored to act as a rudder. Using leg and tail movements on their downward glide, these squirrels are able to change direction in mid-air, ascend and swerve over distances of 50 feet or more.
A typical glide is 20 to 30 feet, but flying squirrels have been observed accomplishing glides of over 200 feet. Upon landing, their habit is to zip to the other side of tree, a learned defense to elude predators.
These squirrels eat a wide variety of foods; acorns and nuts carry them through the winter, and during the rest of the year they eat berries, fruit, flower blossoms and buds, sometimes bird eggs and nestlings, even animal carcasses.
Southern flying squirrels are plentiful in deciduous and mixed deciduous-pine forests — wherever there are mature and dead trees to provide nesting cavities, and there are “fruit” producing trees like oak, hickory, walnut and maple. These squirrels are secondary cavity nesters, which means that they use the nesting holes of other animals and birds.
They will also readily use nesting boxes when cavities are in short supply. Woodpecker cavities are among their favorites and this includes the cavities of red-cockaded woodpeckers.
There is always some competition among cavity nesters for available nesting sites. As the numbers of old dead snags, prime real estate for cavity nesters, have been removed in our forests, the competition for remaining homes has increased.
In situations where a species (such as the red-cockaded woodpecker) is endangered, any additional pressure may be cause for concern. But the southern flying squirrel is only one among many other animals, such as gray squirrels, snakes, other woodpeckers and bluebirds that compete for existing nesting cavities.
Interestingly, it is the exclusion of fire in our region of the state that has changed the makeup of our longleaf pine forests, so they are increasingly mixed with hardwoods. These changed forests in turn attract southern flying squirrels because of the increasing number of fruit or nut producing trees.
The use of prescribed burning in red-cockaded habitat at Fort Bragg, the Sandhills game lands and some private lands in the Safe Harbor Program has allowed these longleaf pine forests to return to their natural condition. In these forests there is little food to attract the southern flying squirrel and some of the other critters that might compete with red-cockaded woodpeckers for their nesting cavities.
In suburban areas, where red-cockaded woodpeckers reside, but prescribed burning cannot be employed, other measures are used to discourage flying squirrels if they become a problem. Restrictor plates can be placed over the hole of an active red-cockaded woodpecker cavity, which keeps squirrels from enlarging the cavity to suit their slightly larger bodies.
During winter, wherever flying squirrels find a nesting cavity they will often nest together to conserve warmth. They tend to breed in early spring and again in mid-summer, producing an average of three to four offspring in a litter. Unless conditions are unusually good, however, the same female seldom has two litters in a year’s time.
It seems that flying squirrels are frequent visitors to our birdfeeders, much like their cousins, gray squirrels. Actually, in many areas flying squirrels outnumber gray squirrels.
We just do not get a chance to observe them because while they are munching most of us are sleeping.
If you are like my friend, however, and tend to prowl about till late at night, try spending some time watching your bird feeders if you happened to have a wooded yard. Keith has found that his squirrels tend to be active from around eleven till the wee hours of the morning.
If you are an early bird, like me, you can still search for signs of flying squirrels. These critters may be tucked away in their nesting cavity while most of us are on the prowl, but they leave a sign of their presence if you just know what to look for.
Unlike other squirrels, flying squirrels have a unique way of cutting a smooth round or oval hole in a nutshell, neatly removing the meat, while leaving the shell intact. Larger nuts, such as walnuts, will have two openings to remove the meat on each side.
I have found such neatly carved shells littering the ground in my back woods. It is a sure indication that a few of these flying squirrels could indeed lay tucked together snoozing just overhead, resting up for a night of sailing and foraging at the other end of the day, under the cover of darkness.
Judy Jessop can be reached though the Sandhills office of The Nature Conservancy at 246-0300.
