Desert Bighorn Sheep
© 1978 Paul Berquist
Desert bighorn sheep (Ovis canadensis nelsoni) have short legs, a narrow muzzle, short pointed ears, a short tail, and generally stocky body. Their coat color ranges from a buff-tan to a gray-tan. Their hair is short and is composed of an outer coat and a fleece under fur. Both rams and ewes have horns, but not only are the horns of an adult ram larger than those of the ewes; male horns curve into a spiral-shape.
Desert bighorn can go without visiting fresh water for days, even weeks. They maintain their body moisture from their plant diet and from drinking rainwater collected in rock pools. They have the ability to lose up to 20 percent of their body weight and still survive. During the heat of the day, desert bighorns rest in the shade of trees, caves, and rock overhangs. They cool their bodies by panting.
Within the desert, preferred habitat of bighorn is primarily on or near mountainous terrain above the desert floor. Because bighorn use their keen eyesight to detect predators, their preferred habitat is open, as well as steep and rocky.
The desert subspecies of bighorn sheep are found from Nevada and California to west Texas and south into Mexico.
Because hunting, loss of food from livestock grazing and transmission of disease from livestock have devastated bighorn sheep populations, they are listed as a species of concern.
Bighorn sheep feed on a variety of grasses, young plants, and leaves. If food is scarce they will eat woody plants and cacti.
Mountain lions are the number one predator of bighorn sheep. Bobcats, coyotes, wolves, and golden eagles are additional predators. While an eagle will not be able to kill an adult they have been known to kill lambs.
The home range of bighorn sheep is quite large, averaging 6.6 square miles. Female sheep will seek out a protected area to give birth to their lambs. Aside from this time the sheep are constantly moving in search of sources of food and water.
On average rams live 9-12 years, while ewes usually live 10-14 years.
Adult desert bighorn rams weigh between 150-200 pounds and ewes weigh between 100-125 pounds. The horns of a male may measure over 33 inches each in length and reach 15 inches in around at the base. Female bighorn have slender, straighter horns that measure 12-17 inches long.
The horns of a male bighorn sheep can weigh as much a 31 pounds.
They can run up to 30 miles per hour on level ground.