Mule deer

Odocoileus hemionus

The mule deer is an iconic American ungulate with a black forehead, gray face, brownish-gray body, white rump patch, and small tail with a black tip. The species is named for its large mule-like ears.

Mature mule deer bucks have antlers with main beams that sweep outward and upward, forking once and then forking again. Mature bucks typically have 4 or 5 points on each side, often including brow tines. The antlers are shed and re-grown each year.

The gestation period for pregnant does is 189 to 210 days and typically one or two fawns are born to each doe. Twins are common in does after their first pregnancy. Fawns are born in late May through early July.

Phylum:

Chordata

Class:

Mammalia

Order:

Artiodactyla

Family:

Cervidae

Subfamily:

Capreolinae

Genus:

Odocoileus

Species:

hemionus

Mule deer management

The Wyoming Game and Fish Department manages mule deer populations through initiatives like the Wyoming Mule Deer Initiative, focusing on habitat restoration and monitoring population health. Public engagement is also important for garnering support for conservation efforts.

Learn more

Mule Deer Overview

Native or nonnative?

Native

Wyoming classification

Big game

Closest relative

White-tailed deer

Scat

Up to ⅞ inches long, pellet-sized and usually with a dimple in one end.

Diet

Herbivore

Top Speed

40 mph

Terminology

Males are bucks, females are does, young are called fawns and a group of deer is called a herd

Mule Deer Population Status

Species of least concern

Lifespan

Typically 9 to 11 years in the wild

The September 2023 cover of Wyoming Wildlife magazine featuring a photo of a mule deer standing in willows

Wyoming Wildlife - Mule Deer Special Edition

Learn more about mule deer in Wyoming in the special mule deer issue of Wyoming Wildlife magazine.

Read the Mule Deer Issue

Mule deer fun facts

Mule deer in western Wyoming migrate over 150 miles seasonally, from the Red Desert to the upper Hoback. This is the longest known mule deer migration in the United States.

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Deer are essentially red-green color blind, but see blue and other short-wavelength colors (such as UV light) much better than we do.

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Mule deer are known for “Stotting”, a jumping gait of locomotion where all four feet hit the ground at the same time, and all four legs are used in the next jump.

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Mule deer's sense of smell is 1,000 times stronger than a human – they can smell a person up to ½ mile away.

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Male (buck) mule deer grow new antlers every year.

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Mule deer are selective feeders, they must select the most nutritious plants and parts of plants.

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These deer get their name from their mule-like ears.

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Mule deer antlers are double forked.

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Predators of mule deer include bears, mountain lions, coyotes and humans.

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Tracks

Height: 1-4 inches long

Width of track: .75-2.5 inches

Stride length: Walking - 13-26 inches | trotting - 29-56 inches

Heart-shaped

Mule Deer Sounds

Mule deer have slight variations in their vocalizations. They may make Low-pitched vocalizations when not disturbed, snorts of alarm and coughed grunts between males.

Mule Deer Sounds

Mule Deer Habitat

Game and Fish focuses on improving mule deer habitat because it has been impacted by extensive drought over the last 25 years, leading to lower survival rates. Wyoming's shrublands, including sagebrush, mountain mahogany, and bitterbrush, provide mule deer with food and cover.

Threats to the species

Common diseases
- Chronic Wasting Disease
- Adenovirus Hemmoragic disease

Vehicle Collisions - 85% of wildlife collisions are with Mule Deer
Invasive and noxious weeds such as cheatgrass have also compromised the integrity of many deer ranges throughout the West
Loss of habitat due to development and subdivisions

Mule Deer Wyoming Distribution

The mule deer’s native range spans throughout western North America, as far north as the coastal islands of Alaska and as far south as Mexico. In Wyoming, mule deer are found from the lower elevation sagebrush deserts and creek bottoms to above timberline in the mountains. Common habitats range from salt desert shrublands to alpine tundra.

Mule Deer Wyoming Population graph

The estimated statewide population of mule deer sits just under 400,000. Also, the Wyoming Game and Fish Department has increased focus on mule deer conservation through the Mule Deer Initiative, which brings together local stakeholders to develop on the ground actions intended to benefit mule deer in select herds.

Mule Deer Where to find and view

Mule deer can be found in nearly all Wyoming habitats. Viewing opportunities are likely near Saratoga, Cody, Kemmerer, or Newcastle in the winter/fall timeframe.

Game and Fish conservation/management efforts

WGFC has committed $3,355,210.25 over the last six years towards nine priority Mule Deer Initiative herds. These funds have been matched by outside funding totaling approximately $21,850,611.28. In total, 68 projects have been funded that address either direct habitat challenges or studies that are designated to target future habitat actions. Additionally, in 2022 WGFC contributed $250,000 towards invasive annual grass mapping and management in important habitats. Game and Fish has selected five focal herds (Laramie Mountains, North Bighorns, Upper Shoshone, Sweetwater, and Wyoming Range herd units) to conduct intensive monitoring on. This endeavor will be a long-term effort and will redefine the way WGFD monitors and manages mule deer in Wyoming. The WGFC awarded this effort $2,355,409.00 in June 2022.