Rocky Mountain Mule Deer | Online Record Book Preview

Odocoileus hemionus hemionus

Venado mula de las Rocosas (Sp), Maultierhirsch (G), Cerf mulet (F). Called mule deer because of its large ears.

DESCRIPTION The usual buck will stand 40-42 inches (102-107 cm) at the shoulder and weigh 175-200 pounds (80-90 kg), but weights of 300 pounds (135 kg) are not uncommon in some areas. The female is smaller.

A medium-sized deer, rather heavily built for a deer, with a thickset body and legs and rather large feet. The ears are long and wide, resembling those of a mule. The antlers of a mature buck are large and widespread. The summer coat is thin and varies in color from tan to rusty-red. The rump, belly and inside of legs are white. Face and throat are whitish, with a black patch on the forehead and a black bar around the chin. Tail is white with a black tip, and sometimes the base of the tail is brown. The underside tail hairs are not erectile and the tail is not used for signaling. The thick winter coat is brownish-gray. Preorbital, tarsal, metatarsal and interdigital glands are present. The metatarsal glands are about five inches (12.7 cm) in length and located closer to the hock than the hoof. (On a blacktail, these glands are 2-1/2 to 3 inches (6.4 to 7.6 cm) in length and are located about halfway between hock and hoof.)

BEHAVIOR Lives in small family groups of does, yearlings and fawns. Bucks are usually solitary, or sometimes in very small bachelor groups. A group is likely to be spread out rather than in close association. The rut begins in October and lasts two months. Dominance fights between males are less competitive than in other deer species, being largely bluff. Fawns (usually two, sometimes three) are born May-June. Life expectancy 8-12 years in the wild, as much as 20 years in captivity.

Feeds mainly in early morning and evening, usually resting at midday and night. Primarily a browser, but will graze on occasion. Mule deer are migratory in mountainous areas, summering as high as 8,000 feet (2,400 m), and retreating to lower elevations in winter to avoid deep snows. Migration distances may be 50 miles (80 km) or more. Senses of smell and hearing are acute, vision less so. Able to run 35 mph (56 km/h) for short distances, but unable to maintain speed for long. Bounds away in a series of high leaps when disturbed. Can cover 25 feet (7.6 m) horizontally in a single leap. A very strong swimmer. Main predators are coyotes, but also cougars.

HABITAT Adaptable to a wide range of western habitat from prairie to alpine to semi-desert, with a preference for open or semi-open country.

DISTRIBUTION Southwestern Canada, and the western United States north of the line established for desert mule deer.

REMARKS A large mule deer buck is a superb trophy and a fine game animal, although perhaps less difficult to take than the sneaky, brush-loving whitetail. Hunted mostly by glassing and stalking, sometimes by waiting on stands. Popular lore holds that a jumped mule deer will always stop after 100 yards (90 m) to look back, but hunters should not count on this, as unwary bucks seldom grow old enough to develop trophy antlers.

TAXONOMIC NOTES Two subspecies listed by Wallmo comprise the SCI Rocky Mountain mule deer category: hemionus (Rocky Mountain mule deer) and californicus (California mule deer), with hemionus Rafinesque, 1817 having priority. The formerly recognized Inyo mule deer (inyoensis) is no longer considered valid and is included within californicus.

STATUS There were millions of mule deer in North America prior to European settlement, but their numbers declined to 500,000 by 1900 after years of market hunting and habitat destruction. Since then, regulation and management efforts have increased numbers to about 5-1/2 million, with an annual sport harvest of 500,000. Populations are secure, and mule deer are expanding their range.