Desert Bighorn Sheep

Ovis canadensis nelsoni

The desert bighorn sheep found in our area are a subspecies (O.c.nelsoni). They are genetically different from sheep found in the Rocky Mountains. In our area they call the mountains of San Jacinto and Santa Rosa their home range. Although not as well built for climbing as mountain goats, bighorn sheep zigzag up and down cliff faces with amazing ease. They use ledges only 2 inches wide for footholds, and bounce from ledge to ledge over spans as wide as 20 feet. They can move over level ground at 30 miles per hour and scramble up mountain slopes at 15 mph. Most populations undergo seasonal movements, generally using larger upland areas in the summer and concentrating in sheltered valleys during the winter. Bighorn sheep are gregarious, sometimes gathering in herds of over 100 individuals, although small groups of 8 to 10 are more common. Mature males usually stay apart from females and young for most of the year in separate bachelor flocks. Young females generally remain in their mother's group (led by an older ewe), but males depart when two to four years old and join a group of rams. Young sheep of both sexes learn migratory paths and suitable habitats from adults in the group.

Family:

Bovidae (antelopes, cattle, gazelles, goats, sheep, and relatives)

Description:

The desert subspecies, Ovis canadensis nelsoni, is somewhat smaller and has flatter, wider-spreading horns then their relatives in the Rocky Mountains. The coat of Ovis canadensis is smooth and composed of an outer coat of brittle guard hairs and short, grey, crimped fleece underfur. The summer coat is a rich, glossy brown but it becomes quite faded by late winter. Rams typically measure 60-70 inches from head to tail, while ewes are somewhat smaller. Desert bighorn sheep can weigh up to 200pounds. Bighorn sheep have double-layered skulls shored with struts of bone for battle protection. They also have a broad, massive tendon linking skull and spine to help the head pivot and recoil from blows. Horns may weigh as much as 30 pounds which is the weight of all the bones in a ram's body. The horns of a female are much smaller and only slightly curved. The horns of a ram can tell much about him such as his age, health, and fighting history.

Habitat:

Desert bighorn sheep prefers steep, rugged, rocky slopes of mountain ranges, areas with adequate food and remote from man. The winter range usually lies between 2,500-5,000 feet in elevation, while the summer range is between 6,000-8,500 feet.

Range:

The general range of O.c.nelsoni is the desert regions of Nevada and California to west Texas and south into Mexico.

Diet:

They are opportunistic herbivores. They forage in a wide variety of plants: mesquite, catsclaw, jojoba, buckwheat, grasses, cactus, agave, etc. Desert bighorn sheep needs water every 3-4 days in summer. Can lose up to 20% of its body weight and replace it at one drinking. Often relies on springs and manmade waterholes.

Breeding:

The reproductive period is called “rut” for rams and “estrus” for ewes and occurs in the fall. While the sexes have roamed in separate bands earlier they will come together in late summer and by fall “rutting” season begins. The dominant ram will do most of the copulating. After a six month gestation period the ewe will give birth to a lamb weighing approximately 8 pounds. Ewes generally return to the same “lambing” areas each year.

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