Deer, a hoofed animal, prized for centuries as game for food, sport, and commercial purposes. Deer are found throughout North America, Europe, Asia, and South America, and in northern Africa. There are nearly 100 different kinds, including the caribou, elk, reindeer, and moose. Largest is the moose, more than six feet (1.8 m) tall at the shoulders. Smallest is the Chilean pudu, almost as small as a rabbit.

The Chilean puduThe Chilean pudu is the smallest of all deer.

Male deer are called stags, bucks, bulls, or harts. Females are does, cows, or hinds. The young are fawns or calves.

Deer are even-toed ungulates—they are hooved animals with an even number of toes on each hoof. They are related to cattle and goats and are like them in having four stomach sections. Food partially digested in one stomach section is returned to the mouth as a cud to be chewed again. Ruminant Deer have solid, branched antlers. Except for the Père David's deer, which grows two sets of antlers a year, deer grow antlers in the spring and shed them in winter. Except for reindeer and caribou, only male deer have antlers. The antlers at first are very tender and covered with velvety hair. Gradually they become hard as stone.

Deer have short-furred coats. Colors range from reddish brown to gray on the upper surface and usually white below. Markings that appear on certain deer are borne on the face, throat, and tail. Young deer are covered with white spots that disappear, in most species, when a new coat of fur is grown.

Some deer live in grasslands where they group together and browse for meadow herbs. Others live in forests and feed on leaves, twigs, buds, and bushes. Deer breed annually in late September. One to three young are born in late spring. Fawns remain with their mothers for about a year. The normal lifespan is 15 to 20 years.