Introduction to Squirrel
Squirrel, a small, active, bushy-tailed mammal. The name comes from the Greek for “shade-tailed.” Squirrels are gnawing mammals, or rodents. They are native to every continent except Australia and Antarctica. There are about 250 species of squirrels divided into two groups—those that live in trees and those that live on the ground. This article is concerned with tree squirrels.
Squirrels are small, bushy-tailed rodents.The squirrel's claws are suited for climbing and for clinging to branches. In jumping, the squirrel's tail acts as a rudder, enabling the animal to hold its course or to swerve.
The squirrel has paired incisors in each jaw. These chisel-shaped teeth can cut into the shell of a nut. The squirrel holds the nut up to its mouth with its front paws. It either gnaws the nut or, keeping its jaws still, twirls the nut against its teeth. Squirrels also eat fruit, seeds, grain, and birds' eggs.
Squirrels commonly live in tree hollows or in nests they build of leaves, twigs, and grass in tree crotches. They may remain in their nests for several days during cold weather. The normal life span of a squirrel is 5 to 10 years.
Squirrels live in tree hollows or in nests of leaves, twigs, and grass.Squirrel skins are used for coats, scarves, linings, and trimmings. The fine, lightweight fur is usually dyed brown, but natural colors are also used. Skins of the best quality come from Europe and Central Asia. The fur of North American squirrels is too sparse and coarse to be of much commercial value. Squirrel meat is edible and in many parts of the world, including the United States, squirrels are shot for game.
Kinds of Tree Squirrels
About 10 species of tree squirrels are found in North America. The most common are included below.
Gray SquirrelsThe eastern gray squirrel is common throughout the eastern half of the United States. The body is about 10 inches (25 cm) long and the tail is about the same length. It usually has rusty-gray outer fur and slate-colored inner fur. Sometimes the coat is black.
The eastern gray squirrel has a very bushy tail and erect, pointed ears. In autumn it stores away nuts and seeds for the winter, placing them in hollow logs, in holes in trees, or under leaves. The squirrel later finds them by its keen sense of smell.
The nest is a bundle of twigs and leaves built high in a tree. There are two breeding seasons, in winter and summer, and usually three to five young are born in a litter in the spring and late summer. The eastern gray squirrel is sometimes hunted for its fur and as game, but otherwise has little economic importance.
The western gray squirrel is slightly larger than the eastern species and has a silvery-gray coat. It is found along the Pacific coast from Washington to Lower California. Another close relative is the Arizona gray squirrel, found mainly in Mexico and Arizona.
The abert, or tassel-eared, squirrel has ears tipped with long tufts. The abert squirrel is found mainly in the mountain forests of Arizona, New Mexico, and Colorado. It has a reddish back and gray sides; its tail is grayish above and white underneath. This squirrel is about 20 inches (50 cm) long, including the 8-inch (20-cm) tail. A subspecies, the Kaibab squirrel, has a whiter tail. This squirrel lives only on the North Rim of the Grand Canyon, on the Kaibab Plateau.
The golden-mantled ground squirrel resembles a chipmunk without facial stripes.Fox SquirrelsThese are closely related to the gray squirrels. The eastern fox squirrel is found in woodlands in the eastern two-thirds of the United States. It is rusty yellowish above, with a paler yellow-to-orange belly. The body ranges from 10 to 15 inches (25 to 38 cm) in length, not including the tail, which is 9 to 14 inches (23 to 36 cm) long. This squirrel spends most of its time foraging for nuts, birds' eggs, and fungi. Two to five young are born in spring and late summer. A similar species, the Apache fox squirrel, is found in Mexico and in the Chiricahua Mountains of southeastern Arizona.
Red SquirrelsThere are two species. One, the red, or spruce, squirrel, is found primarily in forests from Alaska and northern Canada south to New Mexico and the Carolinas. The red squirrel is 7 to 8 inches (18 to 20 cm) long, not including the 4- to 6-inch (10- to 15-cm) tail. It is yellowish or reddish above with a whitish belly. In summer there is a black line along its sides. Two to seven young are born in spring and in summer.
The Douglas squirrel, or chickaree, is somewhat smaller. It is found along the Pacific coast from Canada through parts of California. It is reddish-olive with a yellowish or rusty belly. It also has a black line on its sides in summer. Four to eight young are born in June and October.
Flying SquirrelsThese squirrels live almost entirely in trees and come out only at night. They do not actually fly, but glide. A broad membrane extends between the legs along both sides of the body. When the legs are spread out, the membrane covers a wide area. Supported by air pressure under the membrane, the animal can glide as far as 50 yards (46 m) after leaping from a tall tree.
During the day, flying squirrels sleep in a tree hollow or in a nest. At night, they feed on nuts, fruits, buds, insects, birds' eggs, and birds.
Flying squirrels are found in woods in many parts of the Northern Hemisphere. The northern flying squirrel of Alaska, Canada, and parts of the northern and western United States grows to about 10 inches (25 cm) long, including the 5-inch (12.5-cm) tail. The southern flying squirrel, found throughout most of the eastern half of the United States, is slightly shorter. The fur of both species is reddish-brown above, whitish below. The southern species has two litters of two to six young—one in spring, the other in summer. Northern flying squirrels have two to five young born in May or June.
The giant flying squirrel of southern Asia may grow as long as 36 inches (91 cm) from nose to tail tip. It may be brownish, black, or white. The flying squirrel of Australia is not a squirrel but a phalanger.
Can a Flying Squirrel Really Fly?A flying squirrel does not fly the way a bird does. It cannot fly to a place that is higher than where it started. But when it leaps from a high place, it can glide more than 150 feet (46 meters) to a lower place. The animal has folded skin between its legs. After jumping, the flying squirrel stretches out this skin. The skin catches air and works like a parachute.
Most flying squirrels live in Asia, but some live in North America. These rodents make their homes in tree hollows. Flying squirrels found in North America grow to be 8 to 12 inches (20 to 30 centimeters) long. But those that live in Asia may grow to be 4 feet (1.2 meters) long.
All other kinds of squirrels hunt during the day. But a flying squirrel comes out only at night. Unlike most rodents, flying squirrels are not herbivores. They eat birds’ eggs and insects, as well as berries and nuts. They also eat young birds and carrion, which is the remains of dead animals.
Squirrels make up the family Sciuridae. The eastern gray squirrel is Sciurus carolinensis; the western gray squirrel, S. griseus; the Arizona gray squirrel, S. arizonensis ; the abert squirrel, S. aberti; the Kaibab squirrel, S. aberti kaibabensis; the eastern fox squirrel, S. niger; the Apache fox squirrel, S. apachi; the American red squirrel, Tamiasciurus hudsonicus; the Douglas squirrel, T. douglasi; the northern flying squirrel, Glaucomys sabrinus; the southern flying squirrel, G. volans; the giant flying squirrel, Petaurista petaurista.