Squirrel, the popular name of the rodents of the family sciuridoe, which is very numerous in species, and widely spread over the world, except in Australia. They are characterized by a broad head, the frontal bone being dilated into a post-orbital process; the muzzle wide, from the development of the frontal and nasal bones; eyes large and prominent, ears moderate, and whiskers long; the hind feet five-toed, the fore feet four-toed, with a wartlike thumb, all the lingers and toes with compressed and curved claws; the fur is generally soft, especially in the northern species, and the tail is long, hairy, expanded laterally in the arboreal genera, and shorter and bushy in the terrestrial, and in both carried gracefully over the back; the upper lip is cleft, the caecum large, clavicles perfect, enabling them to use the fore limbs to convey food to the mouth, and the tibia and fibula distinct; some have a membrane extended between the fore and hind limbs. (See Flying Squirrel.) The incisors are f, smooth in front, brown or orange, the lower compressed and sharp; molars rooted, tuberculate, with projecting transverse striae enamelled continuously, the anterior upper one the smallest and sometimes deciduous.
The food is chiefly vegetable, though some American species are known to suck eggs and destroy young birds. The family is very abundant in North America, nearly one third of all the species being found here; the prairie dogs and prairie squirrels are peculiar to this continent, as well as most of the flying squirrels. (See Prairie Dog, and Prairie Squirrel.) - The genus sciurvs (Linn.) is the type of those of the family which live in trees; the species of the United States are hard to determine from the tendency to variation in color (red, gray, and black being the predominating tints), and the diminution in size in the southern states. Baird gives it as a general rule that, when a squirrel has the fur of the throat or belly annulated, it is a variety of some species which normally has the under parts uniformly white or reddish to the roots, or the latter plumbeous. The bones of the red-bellied squirrels are generally red, and of the white-bellied white. The largest of the North American species is the fox squirrel of the southern states (S. vulpinus, Gmel.), about 2½ ft. long, of which the tail is 15 in.; the head is rather slender and pointed, and the tail rather cylindrical; the upper molars are permanently four.
The color varies from a gray above and white below, through various shades of rusty, to uniform shining black; the fur is coarse and harsh, and the ears short; the ears and nose are white in all its varieties. It is found from North Carolina through the S. Atlantic and gulf states to Brazos river in Texas. The gray variety is the S. capistratus (Bosc), and the black the S. niger (Linn.) and the black squirrel of Catesby. It prefers elevated and open pine ridges where there are occasional oak, hickory, and other nut trees; the nest for the winter and breeding seasons is made in a hollow tree, and in summer in the forks between the branches. The young are born in March and April, and fed by the parents for four or five weeks. The food consists of acorns, nuts, fruit of the pine cones, green corn in summer, buds and roots in spring, and whatever it can get in winter, as it does not appear to lay up any winter stores, or to resort to any hoards previously buried. When alarmed, it makes for a hollow tree; it is a swift runner, defends itself boldly, and is very tenacious of life; it is generally seen toward the middle of the day; it is easily domesticated, but is less active in the cage than the smaller species; its flesh is frequently eaten.
The cat squirrel (S. cinereus, Linn.), the fox squirrel of the middle states, is 25 or 26 in. long, of which the tail is about 14 in.; the head is very broad, the muzzle short and catlike, the body thick and heavy, and the tail large and flattened; the color varies from light gray tinged with rusty above and white below, to grizzly above and black below; it is never pure black; the ears are low and broad, and never white; the hair is less coarse and stiff than in the preceding species. It is found chiefly in the middle states, rarely in southern New England; it is rather a slow climber, and of inactive habits; it becomes very fat in autumn, when its flesh is excellent. The species called fox squirrel in the western and southwestern states (S. Lodovieianus, Harlan) has a very full and broad tail; it is rusty gray above and ferruginous below. The common gray squirrel (S. Carolinensis, Gmel., and S. migra-torius, And. and Bach.) is about 22 in. long, of which the tail is 12 in.; the upper molars are permanently five.
The general color is gray above and white below, with a yellowish brown wash on the back and sides; the region behind the ears has usually a white woolly tuft; there is a black variety, the S. niger of Godman. The ears are very high, narrow, and acute, the tail flattened, feet large, claws strong, thumb a rudimentary callosity; the palms naked, and soles mostly so in summer; whiskers longer than the head. It is found extensively over the United States, being much the smallest at the south. The young are four to six, born in May or June. They are easily domesticated and gentle in confinement, and are often kept as pets in wheel cages; they do not lay up any great amount of winter stores, being partially torpid at this season and requiring but little food; they are very fond of nuts, and of green corn and young wheat, on which last account wars of extermination are often waged against them, whole villages turning out to hunt them. At irregular periods they sometimes collect in large troops in the northwest, migrating eastward, crossing rivers and mountains, and committing great destruction in the fields in their course. Many of this species have been domesticated in the public parks of northern cities, where they drive away the birds by destroying their eggs and young.
The California gray squirrel (S. fossor, Peale) is as large as the fox squirrel, but more slender; it is grizzled bluish gray and black above and white below; tail black, white on the exterior, and finely grizzled below; back of ears chestnut. It represents on the west coast the gray squirrel of the east. It runs very swiftly on the ground, not readily taking to trees when pursued; like the other squirrels, it has a kind of bark; the food consists principally of nuts, which it sticks in holes of pine trees bored by woodpeckers, resembling pegs placed in the wood. The red or Hudson bay squirrel (S. Hudsonius, Pall.) has been described under Chickaree. - The common European squirrel (S. vulgaris, Linn.) is about 14 in. long, of which the tail is about one half; the color is reddish, chestnut brown on the back, white below, becoming gray in winter in the north, and yielding then the much prized fur called minever; the ears are tufted, and the hair on the tail is directed to the two sides. It is found throughout Europe and N. Asia; it feeds in summer on buds and shoots, especially the young cones of the pine, and in winter on a supply of nuts which it gathers in autumn and hides in some hollow tree.
It is an excellent climber, and makes a nest of moss, leaves, and fibres very neatly interwoven, in a hole or fork of a tree, and well concealed; a pair live together, frequenting the same tree for many years; the young are born in June, and remain with their parents till the following spring; they are torpid in the very coldest days. The largest of the squirrels is the Malabar squirrel (3. maximus, Schreb.), 33 in. long, as large as a cat; it is black above, the sides and top of head chestnut, and lower parts pale yellow; it lives in palm trees, feeding on the cocoanut. - The ground squirrels (tamias, Illig.) have been described under Chipmunk.
Common Gray Squirrel (Sciurus Carolinensis).
Common European Squirrel (Sciurus vulgaris).