Know Before You Go

Bighorn sheep are perhaps best known for their high-speed, forceful collisions with competitors. In these jousting matches, they can generate hundreds of pounds of force, far more than is needed to crack a human skull.

PHYSICAL CHARACTERISTICS

The bighorn sheep’s fur is tan or brown with a white muzzle, rump and stomach. The ram’s large horns can weigh 30 or 40 pounds, representing more than 10 percent of total body weight. The ewe’s, or female’s, horns are thinner and straighter. Males weigh anywhere from 125 to 300 pounds; the females of this species are smaller, weighing between 75 and 200 pounds. Bighorn sheep are skilled climbers and jumpers. Their rubberlike hooves help them grip onto slippery rocks and steep ledges in Yellowstone and the Grand Tetons.

FEEDING HABITS

In the summer, bighorn sheep graze on clover, sedges and grasses. During colder months, they eat woody plants like willow and sage, and in desert regions, they browse on brushy plants such as cactus and holly. When not grazing, these creatures will lie down and chew their cud.

BEHAVIOR & BREEDING

In autumn, rams establish their dominance through head butting contests and will typically only challenge males with similar-sized horns. They charge at speeds of up to 20 miles per hour, ramming their heads together in a duel that can last upward of 20 hours! The dominant ram will mate with more females than the other rams. When a male is ready to mate, he will go into a herd of females. The female will chase the male before they mate, and sometimes, a male will kick a female to get her to chase him.

Females typically give birth to their single offspring on a cliff that is difficult to access. Lambs are born woolly and white with little horns. For the first week of its life, the lamb stays in seclusion where it was born, then begins to follow its mother. Although they can walk and climb by the first day, the young are not weaned until about 5 months of age. Males leave their mother and join a bachelor group at 2 to 4 years of age, while female lambs will typically remain with their mother’s group for their entire lives.