© Joseph Dougherty. All rights reserved.
Ovis canadensis nelsoni
Desert Bighorn Sheep
Bighorn Sheep Ram grazing on plateau plants atop a high "sky island" mesa. Canyonlands National Park, Utah.
Bighorn sheep are named for the large, curved horns borne by the rams (males). Ewes (females) also have horns, but they are shorter with less curvature. They range in color from light brown to grayish or dark, chocolate brown, with a white rump and lining on the back of all four legs. Males typically weigh 127–316 pounds (58–143 kg), are 36–41 inches (91–100 cm) tall at the shoulder, and 69–79 inches (180–200 cm) long from the nose to the tail. Females are typically 75–188 pounds (34–85 kg), 30–36 inches (76–91 cm) tall and 54–67 inches (140–170 cm) long. Male bighorn sheep have large horn cores, enlarged cornual and frontal sinuses and internal bony septa. These adaptations serve to protect the brain by absorbing the impact of clashes. Bighorn sheep have pre-orbital glands on the anterior corner of each eye, inguinal glands in the groin and pedal glands on each foot. Secretions from these glands may support dominance behaviors.