Today's squirrel (family Sciurdae, order Rodentia) includes tree and ground squirrels, prairie dogs, chipmunks, marmots and woodchucks. The gray squirrel weighs one to two pounds and averages 20 inches in length. In summer, the gray squirrel is reddish brown, and in winter is shaded silver. There are also white (albino) and black (melanistic) gray squirrels. Black squirrels are fairly common in the North; white squirrels are rare and local (one isolated pocket of 1,000 white squirrels occurs near Olney, Il. -there are stiff fines to motorists who hit those albino squirrels).
The word squirrel comes from the Greek "skiouro" or "he who sits in the shadow of his tail." The squirrel's tail has many diversified functions: a warm wrap in winter, balance when running or jumping, rudder when swimming, parachute when forced into the air, and distraction to predators.
The squirrel's longevity can be 9 to 10 years in the wild (females live longer than males), and 15 years in captivity. The approximate age can be determined by looking at the tail. Juvenile squirrels have 2 or 3 dark bands running through the brown primary hairs. The bands gradually fade with age and vanish in adulthood.
Gray squirrels inhabit hardwood forests, small woodlots, city parks-all places that provide them with acorns, beechnuts, hickory nuts, butternuts, and black walnuts. (Most squirrel feeders feature peanuts, the squirrel equivalent of fast food and not especially good for them.) The average gray squirrel consumes about 2 pounds of food a week-not only nuts, but fruits, vegetables, and grains. They also eat twigs, flower bulbs, mushrooms, and the sweet sap of sugar maple and birch trees.
Squirrels have a double set of chisel shaped gnawing incisors, which are common to all rodents. These teeth continue to grow throughout life (as much as 6 inches a year). They must be constantly worn down by chewing and gnawing-or else the teeth will continue to grow, curving into the jaws. They will gnaw on almost anything, including the coverings of telephone lines (causing phones to crackle).
One common habit of squirrels is to bury nuts-each nut placed in a little cup shaped hole about 3 inches deep. It is estimated that each gray squirrel buries at least 1,000 nuts every autumn, possibly as many as 10,000. The squirrel locates its stored nuts by its keen sense of smell, able to locate a nut buried under a foot or more of snow. The imperfection of nut-retrieval is why the squirrel is a called the "Forest Planter" -many new trees develop.
Squirrels breed once or twice a year-first in midwinter, then possibly again in May or June. The young are born from late February to the end of April, a second batch in late July or August. Gray Squirrels take two years to reach full size.
Squirrels are the fastest rodents, with top recorded running speeds of 17 m.p.h., more normally 10 m.p.h. The champion leaper is the flying squirrel, of which there are two varieties, northern and southern, in North America. The flying squirrel makes soaring leaps of up to 150 feet, gliding at 5 m.p.h. The squirrel flattens out in flight, extending wing-like membranes, loose flaps of skin that stretch from front to hind limbs. North American flying squirrels are tiny, weighing only 3 ounces and measuring about 10 inches in length. Flying squirrels are nocturnal and are said to make delightful pets.
The red squirrel, about half the size of the gray, frequents evergreens. The fox squirrel, found throughout the eastern U.S., except in New England, is the largest of the group, weighing up to 3 pounds and measuring 2 feet in length. Fox squirrels can be rusty yellow, grizzled, or black and white. They are active in the middle of the day, when the grays are napping.