Squirrel

Squirrel, common name for many rodents belonging to the same family as the woodchuck (see Marmot), chipmunk, and prairie dog. The tree squirrels, characterized by their long bushy tails and agility among the trees, and ground squirrels include about 230 species. The so-called flying squirrels include about 43 species. Squirrels range in size from the pygmy squirrels of Africa, which are about 13 cm (5 in) long, to the giant squirrels of Asia, which are about 90 cm (36 in) long. The animals exist in all parts of the world except Australia.

Except for the ground squirrels, the animals live mainly in trees (their nests are called dreys), and their food is largely vegetable (especially nuts, seeds, and buds), although they occasionally eat insects. Their habit of storing seeds helps in the dispersion of trees and other plant forms. In colder climates, ground squirrels commonly hibernate; tree squirrels do not.

One of the most common and widely distributed species is the red squirrel, which ranges throughout Europe (except most of mainland Britain where it usually only survives in coniferous forests, mostly in southern Scotland) and northern Asia. It has reddish-brown fur, which turns darker brown in winter, and grows to a length of 24 cm (9y in) with a tail up to 20 cm (8 in) long. The grey squirrel is a familiar dweller in city parks and, since its introduction from the United States into Britain, has displaced the native red squirrel in many areas. It is larger than the red squirrel, up to 30 cm (12 in) long with a tail that reaches up to 25 cm (10 in) in length, and more robust. It has grey fur but its flanks are sometimes reddish. They are often considered pests as their habit of eating bark leads to the death of trees. Both the red and grey squirrels give birth to one to three young in a litter after a gestation period of up to about 42 days. The offspring become independent at 10 to 16 weeks.

In the Great Plains region of the United States are found the ground squirrels, of which the 13-lined ground squirrel is a common variety.

Flying squirrels have a folded layer of loose skin along each side of the body, from the front to the hind leg. When outstretched, this skin supports the animals as they glide from tree to tree. In Africa, another rodent family contains squirrel-like gliders called scaly-tailed flying squirrels.

Scientific classification: Squirrels belong to the family Sciuridae. Tree and ground squirrels belong to the subfamily Sciurinae, and flying squirrels belong to the subfamily Petauristinae. The pygmy squirrels of Africa make up the genus Myosciurus and the giant squirrels of Asia the genus Ratufa. The red squirrel is classified as Sciurus vulgaris, the grey squirrel as Sciurus carolinensis, and the 13-lined ground squirrel as Spermophilus tridecemlineatus. Scaly-tailed flying squirrels belong to the family Anomaluridae.