The mule deer (Odocoileus hemionus) is a native medium-size mammal of the western United States. It earns its name because of its unusually large ears which is similar to the mule. The mule deer is likely to be smaller in size than the white-tailed deer. They have acute sense of hearing and eyesight with the help of which they can sense danger from far off.
Mule Deer Facts
- Mule deer are clearly different from their cousin white-tailed deer not only in the size but also in the size of their ears. The white-tailed deer has got small ears.
- The tip of the mule deer’s tail is black while white-tailed deer lack one.
- Males are called ‘buck’ and they are mainly recognized by their forked antlers. Females are known as ‘doe’.
- There is a white rump patch on the deer’s tail that usually acts as a silent alarm signal to conspecifics. When they lower down their tail, the predator that is looking at the deer may not be able to see.
- They may regrow their antlers if the old ones are shed. The old antlers are shed in February while the new ones grow in the spring season.
- While mule deer are fast runners they also perform ‘stotting’—an act in which the deer lifts all its four legs and come down in the same way. It’s like a deer are enjoying like a human-kid.
- Adult deer stand 80–106 cm (31–42 in) tall at the shoulder.
- The total length of a deer reaches at 1.2 to 2.1 m (3.9 to 6.9 ft) including 11.6 to 23 cm (4.6 to 9.1 in) long tail.
- Adult males average 55–150 kg (121–331 lb) in weight while females weigh 43 to 90 kg (95 to 198 lb).
Feeding Ecology & Diet
- The winter diet of a mule deer consists of shrubs and trees (74%) while other grasses and forbs make up only 15 – 20 percent of the diet. Similarly during spring the deer rely more on forbs (25%) and relatively less on shrubs and trees (49%).
- The summer diet is equally composed of shrubs, trees, and forbs. They also supplement their diet with some fruits including acorns, berries, beans, nuts, oak nuts, and pods.
- Mule deer feeds on a range of different plants some of which are true mountain mahogany, antelope bitterbrush, common juniper, skunkbush sumac, western yarrow, gambel oak, Mexican cliffrose, fringed sagebrush, dandelion, American vetch, bluebunch wheatgrass, creeping barberry, Idaho fescue, Kentucky bluegrass, and big sagebrush.
- The mule deer are also thought to consume black oak, cottonwood, ricegrass, California buckeye, knotweed, goldeneye, snowberry, velvet elder, scrub oak, creek dogwood, needlegrass, Manzanita, jack pine, rabbitbrush, cedar, sunflower, Douglas fir, silktassel, wild oats, and black oak.
- They will come out to forage in dawn and dusk.
- Mule deer are likely to make habitats in rocky, dry, south-facing slopes where vegetation grows in small number.
- The mating season or ‘rut’ of a mule deer begins in November – December.
- Fawns are usually born in late May and late June.
- The gestation period typically lasts 202 days.
- Fawns weigh up to 7 – 8 pounds at birth. They will gain weight in the first 14 days.
- The average litter size is 1 – 2 fawns but sometimes the litter size can be three.
- The female attains maturity at 6 – 7 months but normally she begins mating at 18 months of age.
- Fawns will leave their parents in about 60 – 75 days.
- Predators of mule deer include coyotes, bobcats, brown bears, cougars, wolverines, American black bear, and gray wolf.