a genus of artiodactyls of the family Cervidae. The body length is 1.5–2 m, the height is 0.8–1.1 m, and the tail length reaches 28 cm. The animals weigh up to 145 kg. There are two species, the whitetail (O. virginianus) and the mule deer (O. hemionus). Both species are found in the Americas. The males have branched antlers, and the females are hornless. The deer occupy a variety of habitats. They live in groups of two to four and feed on vegetation. The deer are popular game animals. They are hunted for their meat, hide, and antlers.