First listed on March 18, 1998. Range: California.
Credit: U.S. Fish & Wildlife Service
Rams are male bighorn sheep, animals that live in the mountains and often settle arguments with fights that include ramming their heads into others. Not to be confused with mountain goats, rams can be identified by their long, curved horns; long fur; and split hooves. Some of the ram's relatives are goats, bison, buffalo, antelopes and cattle, according to the Integrated Taxonomic Information System (ITIS).
Rams are typically 5 to 6 feet tall (1.5 to 1.8 meters) from head to tail, and weigh 262 to 280 lbs. (119 to 127 kilograms). Rocky Mountain bighorn rams have massive horns that weigh more than all of the bones in their bodies. A set of horns can weigh 30 lbs. (14 kg).
Bighorn sheep live in the Rocky Mountain region of North America, ranging from Mexico, northward across the western United States and into Canada. They live in the rocky areas, balancing on the boulders with their hooves, which are rough on the bottom to give the sheep more traction. Thanks to their amazing balance, bighorn sheep can stand on ledges that are only 2 inches (5 centimeters) wide. They can also jump 20 feet (6 m) and can go up a mountain at a brisk 15 mph (24 km/h). The only better mountain climbers in the animal world are mountain goats.
Desert bighorn sheep, a subspecies, live in Death Valley, California, as well as Nevada, Texas and northern Mexico. They can live on desert mountains as high as 4,000 feet (1,200 m). They get most of their water from eating plants to survive, according to the Natural History Museum of Los Angeles.
Rams are herbivores. They typically eat seeds, grass and plants.
One swallow of food isn't enough for these animals. They will regurgitate their food into their mouths. This regurgitated food is called cud. Then, they will rechew the food and swallow it once again. This is part of their digestion process.
Rams are social, but herds are separated by gender. Male-only bachelor herds usually contain five to 50 rams at one time. The females live in nursery herds, with five to 100 members, which include adult females and lambs of both genders.
Rams fight to decide who will be the dominant male in their group. During the fight, the males will face each other, rear up on their back legs and crash their huge horns into each other. Sometimes they charge as fast as 40 mph (64 km/h). Eventually, one of the rams ends up submitting and the winner is the new leader. This process can take hours.
Rams also fight for the right to mate with the females. The strongest rams of the herd will mate with the females. Mating season, called the rut, is in the autumn. Males are not usually strong enough to mate until they are at least 3 years old.
Female bighorns are pregnant for about 175 days, or about 25 weeks. They usually have only one lamb at a time. In the spring, the young are born on high ledges that protect them from predators.
Lambs are dependent on their mothers for the first four to six months of their lives, though they can walk almost as soon as they are born.
The taxonomy of bighorn sheep, according to the Integrated Taxonomic Information System (ITIS), is:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Artiodactyla
- Family: Bovidae
- Subfamily: Caprinae
- Genus and species: Ovis canadensis
- Subspecies: Ovis canadensis auduboni (Badlands bighorn or Audubon's bighorn sheep, which is extinct), Ovis canadensis californiana (California bighorn sheep), Ovis canadensis canadensis (Rocky Mountain bighorn sheep), Ovis canadensis cremnobates (Peninsular bighorn sheep), Ovis canadensis mexicana (desert bighorn sheep or Mexican bighorn sheep),Ovis canadensis nelsoni (Nelson's bighorn sheep or desert bighorn sheep) and Ovis canadensis weemsi (Weems' bighorn).
Bighorn sheep are not endangered, according to the International Union for Conservation of Nature. It is estimated that there are 15,500 to 15,700 bighorn sheep in Canada and more than 42,000 in the United States. It is believed that there could be several thousand bighorns in Mexico. Almost all bighorn populations are increasing or stable.
ITIS lists one subspecies, Ovis canadensis auduboni, the Badlands bighorn, as extinct.
Nina Sen contributed to this article.
- National Geographic: Rocky Mountain Bighorn Sheep
- National Park Service: Bighorn Sheep
- National Wildlife Federation: Bighorn Sheep
- Natural History Museum of Los Angeles: Bighorn Sheep