Sheep, Desert Bighorn

Bighorn Sheep Male at the L.A. Zoo (Photo by Jamie Pham)

Scientific Name: Ovis nelsoni

The male bighorn sheep’s horns are one of the most easily identifiable in the animal world. Those majestic circular horns have been used as logos in advertising for a popular model of truck for many years. Can you name the auto manufacturer that uses the ram’s head as its logo and the slogan “Built Ram-Tough”?

The Biggest Horns Win!

As members of the bovid family, both male and female sheep have horns, but the male’s horns are much bigger than the female and size often determines who “gets the girl.” Bovid horns are made of a bony core attached to the skull, with an ever-growing sheath made of keratin, the same substance that human hair and fingernails are made of! The horns are permanent (unlike deer antlers) and are made of bone.

Age and horn size determines male dominance, although head-butting clashes between males are used as a way to prove dominance and gain access to a particular female during mating season. Younger males engage in these fights more frequently, and older males, with their bigger and stronger horns, will win the match very quickly. Head butting clashes have been known to last for hours and sometimes days!

The desert bighorn sheep has been listed as Least Concern.

Bighorn sheep live in grassy mountain slopes, alpine meadows, and foothill country from Nevada and California to west Texas and south into Baja California. There is a rare herd that lives in the Sierra Nevada Mountains. They prefer dry, rocky cliffs, and bluffs where they can hide and run away quickly from predators.

Bighorn sheep are grazers. They eat all types of grasses and brush and will eat twigs and leaves when necessary. In the desert, their diet includes all kinds of cacti, yucca, and fruits. They get most of their moisture from the desert plants, but still need to visit water holes every few days during the summer months.

The most recognizable characteristic of the bighorn sheep are the male’s massive, spiraled horns and their majestic faces. Females, or ewes, are smaller than the male, and have smaller, shorter horns that also curve into a spiral shape, never exceeding a half a curl. They are brownish in color with white rumps and a short tail. The eyes are set on the sides of the head; the ears are short and pointed. They have very acute eyesight and hearing, which helps them navigate through their rocky terrain and avoid predators. Their faces are narrow and pointed.

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