Mule Deer, a common deer of western North America. It is found in western Canada and from the western United States south to northern Mexico. It is named for its large mulelike ears, which grow to a length of up to 6 ½ inches (16.5 cm). Because of its blacktipped tail, the mule deer is also referred to as the black-tailed deer. The buck (male) is 3 to 3 ½ feet (about 1 m) tall at the shoulder and 5 to 6 feet (1.5 to 1.8 m) long. The doe (female) is about two-thirds as large. A buck weighs 125 to 400 pounds (57 to 180 kg); a doe, 100 to 150 pounds (45 to 68 kg). In both sexes the coat is mostly tawny to yellowish-brown in summer and grayish in winter. The forehead and underparts are darker; the throat and inner sides of the legs are white. Mule deer have a white rump patch. Antlers, grown only by the buck, are shed in winter. The mule deer has a characteristic bounding gait.

Mule deerMule deer are named for their large, mule-like ears.

Mule deer feed mainly on berries, twigs, grass, and shrubs. They are primarily solitary animals but occasionally gather in herds in winter. Mule deer breed in November. After a gestation period of about seven months, the doe gives birth to one to three—most commonly, two—fawns. Fawns are born with spotted coats. Mule deer reach maturity in about 2 years and live about 10 years.

The coast, or Columbian black-tailed, deer is a subspecies of the mule deer. It is slightly darker in color and has a solid black tail. It is found along the Pacific coast in Washington and Oregon.

Mule deer belong to the deer family, Cervidae. The mule deer is Odocoileus hemionus; the coast deer, O. h. columbianus.