Bighorn sheep (Artiodactyla: Bovidae: Ovis canadensis) can be found in many mountainous areas of the North American west. Scattered from Colorado’s Front Range to California’s Sierra Nevada Mountains and from Canada’s Northern Rockies to Baja Mexico, these large mammals are at home wherever rocky slopes give them an advantage against predators. These giants make their way from one meadow to the next feeding on a variety of grasses, woody stems, and some evergreens. Along the way they use their impressive cliff climbing skills to avoid and escape mountain lions, bobcats, lynxes, wolves, coyotes, and golden eagles, although it’s usually the lambs that become prey.
These large sheep climb like expert mountaineers thanks to the unique structure of their hooves. The outside edges are hard and cut into rock, snow, and ice to establish a solid footing. The soft middle part grips rock like the rubber sole of a boot. If a sheep starts to lose its footing, the split hooves spread and clasp the ground even more firmly. Although many predators can pursue these sheep up cliff faces, they lack the adaptations that give the sheep an edge.
Bighorns are social animals, and throughout much of the year they’re split into two distinct groups. Rams generally herd together apart from ewes and lambs, but they come together during the late autumn rut. During the mating season males bash their horns together to establish dominance and mating rights. While rams can exceed 300 pounds in weight, their horns alone can exceed 30 pounds.
Lambs are born in the spring, usually atop remote ledges to protect them from predators. They can walk within one day and can scale cliffs with their herd a few days after that. With so many predators it’s essential that the young get moving quickly.
Although there are several subspecies of bighorns, it’s the Rocky Mountain bighorns shown here that are the largest and best-known. These tough, resilient creatures are the state animal of Colorado as well as the official symbol of the Colorado Department of Wildlife.