Sheep Information We Should Know
Bighorn Sheep (Ovis Canadensis) are beautiful and majestic creatures, with rams having large brown horns curling around, under and forward. They are typically found in the higher elevations near water sources or rocky cliff areas. They eat grasses and other plants. Bighorn Sheep have hooves adapted to steep, rocky terrain and use their climbing abilities to escape predators.
Big Horn Sheep
Male sheep are called rams. They weigh 140 to 220 pounds and they can be recognized by their large curling set of horns. Their horns will curl back over their ears, down and back up past the cheeks. A mature ram (seven or eight years old) will have a set of horns about 30 inches long and spread about 30 inches wide. The set will weigh about 30 pounds. Even though the size of the horns is a symbol of rank in the herd, many rams will rub off the ends against a rock (brooming) as the ends will tend to interfere with their vision. The shorter horns on a female, called a ewe never extend past half a curl. The ewes are also smaller in size than rams, weighing from 75 to 130 pounds.
Seasonal Water Needs
In the winter, when green grasses are available, bighorn do not need to drink. However, in the hot summer months, they need to visit waterholes at least every three days. Ewes with nursing lambs need to drink nearly everyday. They can tolerate a reduced body weight of up to 20% as a result of water loss. They often look emaciated when arriving to drink. Within minutes they can replenish the lost water and appear trim and strong. The capacity to drink quickly and replenish lost water is most likely an adaptation to increased predation around water sources.
Bighorn have extremely acute eyesight, which helps them spot ledges and footholds when moving about steep terrain. They can spot and watch animals at a distance of nearly a mile away.
Diet and Digestion
The bighorn typically use open areas of low growing vegetation near steep, rugged terrain for feeding. They graze and browse a wide variety of plant species, but green grasses are preferred. Bighorns have a complex digestive process that maximizes removal of nutrients from their food. By passing food from one stomach compartment to another and chewing in between, nutrients are efficiently absorbed and only concentrated dry droppings remain.
Only about one of three lambs born during the spring will survive the first summer, falling victim to the dangers described as being inherent to bighorn. Ewes will be ready to breed in about the third year. Rams will be ready about the same age but are not usually large enough to compete with older, larger males until they are about seven years old. On the average, Bighorn Sheep live to about 10 years old with a maximum life span of 20 years.
Bighorn Sheep are highly susceptible to certain diseases carried by domestic sheep such as scabies and pneumonia; additional mortality occurs as a result of accidents involving rock fall or falling off cliffs are hazards of living in steep, rugged terrain.
Source: Washington State Department of Fish and Wildlife | Learn more about sheep