Ovis canadensis

They form seasonal herds—rams (males) gather apart from ewes (females) outside the breeding season, while mixed groups emerge during fall rut. Agile climbers, they use sheer cliffs and ledges to escape predators and forage on grasses, shrubs, and forbs.

Rut (mating season) occurs in late fall when rams clash horns in dramatic head-to-head battles to establish dominance and gain access to ewes. After a gestation of about six months, ewes typically give birth to one—occasionally two—lambs in spring, which remain close to their mothers until the following winter.

Adult rams weigh 65–110 kg (145–240 lb) with horn curls exceeding 30 kg (66 lb) of bone; ewes are smaller (45–68 kg or 100–150 lb) with shorter, slimmer horns. Their specialized hoof structure—hard outer rim and soft inner pad—gives exceptional grip on rocky surfaces.

Once widespread across North America, bighorn populations plummeted in the 19th and early 20th centuries due to overhunting, disease transmission from domestic livestock, and habitat fragmentation. Early conservation efforts, including translocations and habitat protection, helped many herds recover.

The IUCN lists bighorn sheep as Least Concern overall, though several subspecies (e.g., Sierra Nevada bighorn) remain endangered or threatened. Ongoing management focuses on disease prevention, habitat connectivity, and careful monitoring to sustain and expand healthy populations.