IV.

Behavior

Many deer species group into families around the female, commonly known as a doe, with the male often becoming solitary; others, such as the musk deer and Chinese water deer, live mainly in pairs. The red deer, which are gregarious, associate in small to large herds, each led by a mature female. Caribou migrate between the forest and the treeless tundra in herds of a thousand or more.

Deer forage on twigs, leaves, bark, and buds of bushes and saplings and on grasses and other plants, feeding most actively at twilight. The female gives birth once a year, usually to one or two fawns. The gestation period lasts from 160 days in musk deer to ten months in roe deer; this long gestation in roe deer is accounted for by a delayed implantation. Fawns are kept hidden in thickets, camouflaged by their usually dappled markings. In the United States, where deer now have few natural predators, they often overbrowse their territory and may die of starvation, especially during winters of deep snow. Hunting seasons are adjusted accordingly.