California Mule Deer

Odocoileus hemionus californicus

Physical Characteristics

It is named for its ears, which are large like those of the mule. There are believed to be several subspecies, including the black-tailed deer. One of the principal means of distinguishing the closely related black-tailed deer and white-tailed deer is the growth habit of the buck’s antlers. In the case of the California mule deer, the antlers fork in an upward growth, whereas the other species’ antlers grow in a forward direction.

The mule deer’s tail is black-tipped. Mule deer antlers are bifurcated; they “fork” as they grow, rather than branching from a single main beam. Each spring, a buck’s antlers start to regrow almost immediately after the old antlers are shed. Shedding typically takes place in mid-February, with variations occurring by locale. Although capable of running, mule deer are often seen stotting (also called pronking), with all 4 feet coming down together.

The mule deer has a height of 31 – 42 in (80-106 cm) at the shoulders and a nose to tail length ranging from 3.9 to 6.9 ft (1.2 to 2.1 m). Adult bucks (male deer) normally weigh 120 – 330 lbs (55 – 150 kg), averaging around 200 lbs (92 kg), Does (female deer) are rather smaller and typically weigh from 95 to 200 lbs (43 to 90 kg), with an average of around 150 lbs (68 kg).

Habitat

Generally, the California mule deer has a preference for hill terrain, especially an oak woodland habitat. It is a browser and will typically take over 90% of its diet from shrubs and leaves and the balance from grasses.

Diet and Behavior

California mule deer usually browse close to lakes or streams providing their water source. From that reference point of water consumption they may roam 1 to 2 miles, and typically make their beds in grassy areas beneath trees within such a 1 mile distance radius from both water and forage. Repeated beds will often be scratched to a nearly level surface, about 2 meters in diameter. Less regularly used bedding areas are manifested as flattened grass. On hot summer days California mule deer often seek shade and rest in the mid-day.

In summer, California mule deer mainly browse on leaves of small trees, shrubs and herbaceous plants, but also consume many types of berry (including blackberry, huckleberry, salal and thimbleberry). In winter, they may expand their forage to conifers (particularly twigs of douglas fir, aspen, willow, dogwood, juniper, and sage). Year-round, they feed on acorns; grasses are a secondary food source. Where humans have encroached on historic deer habitat by suburban development or orchards, California mule deer will diversify their diet with garden plant material, with fruit trees, and occasionally, even with pet food.

Fawns and Does tend to forage together in familial groupings while bucks tend to travel singly or with other bucks. California mule deer browse most actively near dawn and dusk, but will also forage at night in open agricultural areas or when experiencing hunting pressure.

Breeding

Rutting (mating) season occurs in autumn when does come into estrus for a period lasting only several days. Males manifest aggressive behavior in competing for mates. Does will begin oestrus again if they do not mate. The gestation period is approximately 200 days, with fawns arriving in the spring; the young will remain with mothers throughout the summer and become weaned in the autumn. Mule deer females usually give birth to two fawns, although if it is their first time having a fawn, they often only have one. The buck’s antlers fall off in the winter-time and commence growing once more in spring in anticipation of next autumn’s rut.

Predators

The several predators other than humans of mule deer include mountain lions. This leading natural predator often select weak, sickly, or young deer to kill, but will also take down the largest and healthiest mule deer with some regularity, as well. Bobcats, coyotes, black bears are capable of preying on adult deer, but usually either only attack fawns or infirm specimens or eat the deer after it has died naturally.

References

Mule Deer, from Wikipedia, the free encyclopedia

California Mule Deer, from Wikipedia, the free encyclopedia