Mule Deer
Author: Anne Schultz


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Scientific Name: Odocoileus hemionus
Common Name: Mule Deer
Spanish Name: Ciervos de la Mula

Description:
Mule deer weigh between 94 and 330 pounds. Males are usually larger than females. These deer stand between 2 and 3 feet tall at the shoulder. Their coats can be light or dark gray, brown, or even reddish. Mule deer have a white patch on their throats and a white or yellowish rump patch. The tip of a mule deer's white tail is often a tuft of black hair. Mule deer may have a black stripe running along the spine.

Geographic Range:
Mule deer are found throughout New Mexico. In New Mexico, the Rocky Mountain mule deer is found throughout the northern 2/3 of the state and the desert mule deer is found in the southern third.

Habitat:
New Mexico mule deer are found throughout all elevations and habitats, but are rare in the open grasslands of the eastern plains. They use a mix of habitats throughout the year. Higher elevation conifer forest edges, aspen groves, and meadows are a good place to live throughout spring and summer. In the fall and winter, deer are frequently found in piñon-juniper woodlands.

Food web:
Mule deer are herbivores. They eat a variety of plants throughout the year, depending on the season and where they live. They eat grasses, shrubs, trees, and even mushrooms! Some of the common plants eaten by mule deer are:

Oak
Juniper
Mountain mahogany
Piñon
Bitterbrush/Antelope brush
Douglas fir
Ponderosa pine
White Fir
Sagebrush
Rice grass
Serviceberry
Fescue

Mexican wolves, mountain lions, coyotes, and black bear, and humans hunt mule deer. Hunting adult male deer (bucks) is permitted in parts of New Mexico at certain times of the year and with a permit. The New Mexico Department of Game and Fish determines and enforces hunting regulations.

Reproduction and Development:
Mule deer usually breed between late November and mid December. Only dominant males (usually the largest) will mate. Females usually mate for the first time when they are two years old. It usually takes about 204 days (6 to 7 months) for the young mule deer to develop within the uterus (gestate), so most young are born the following June. Mule deer twins are common. Young deer are weaned by the time they are four months old.

Behavior:
Mule deer are social animals, but males and females live separately (except for during mating season). Females and young deer live in herds, which are based on maternal relationships (their relationships to their mothers). Adult males typically form small groups of unrelated individuals. Deer live in different parts of their range during the summer and winter months. They move to higher elevations in the summer and move to lower elevations in winter to avoid deep snow and cold temperatures. In the southwest, mule deer will also migrate in response to rainfall patterns in order to find food.

Conservation:
Mule deer populations have been decreasing within New Mexico for some time. The biggest threats to mule deer is the loss of their habitat due to humans moving into their territory and chronic wasting disease.

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Taxonomy:

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Artiodactyla
Family: Cervidae
Genus: Odocoileus
Species: Odocoileus hemionus

Two subspecies of mule deer are known for New Mexico – the Rocky Mountain mule deer (Odocoileus hemionus hemionus) and the desert mule deer (Odocoileus hemionus eremicus).

References:
Species information was obtained from the Biota Information System of New Mexico (BISON) and the University of Michigan's Animal Diversity Web (http://animaldiversity.ummz.umich.edu/index.html).

Related Terms: odocoileus hemionus