Bighorn sheep

The bighorn sheep (Ovis canadensis) is a species of sheep that lives in the western half of North America.Allen J.A. 1912.   
Historical and nomenclatorial notes on North American sheep. Bulletin of the AMNH v. 31, article 1 Their name comes from their large horns. Their horns can weigh up to 30 pounds (14 kg). However, the sheep themselves weigh up to 300 pounds (140 kg). 

Genetic testing showed that there are three subspecies of bighorn sheep:
Sierra Nevada bighorn (O. c. sierrae) (endangered)
Desert bighorn (O. c. nelsoni)
Rocky Mountain bighorn (O. c. canadensis)
Ovis canadensis auduboni (extinct)

Appearance
Adult male bighorn sheep can weigh 350 lbs (159 kg) and stand 40 inches (102 cm) tall at the shoulder.  Adult female sheep are as heavy as 250 lbs (113 kg).  They are grayish brown to dark brown in color with white faces and rear ends.  This makes them difficult to see when the ground is part snow and part grass.

Their hooves are rough on the bottom.  This allows the sheep to climb, walk, and jump in steep, rocky places.

All bighorn sheep have horns.  They stay on their heads their whole lives.  They do not fall off the way antlers do.  Male bighorn sheep have large, curved horns that curl around their faces.  Female bighorn sheep have shorter horns with sharp points.

Behavior

Bighorn sheep live in herds.  Male sheep live in herds with only other adult males.  These are called bachelor herds.  Female sheep live in herds with other adult females and lambs.  When male sheep are two years old, they leave their mother's herd and find a bachelor herd.

Bighorn sheep eat many kinds of plants.  They have four-part stomachs.  They feed on plants in lowlands and then go back to the rocks, where they can chew their cud and digest the food. Desert sheep can eat cacti.

When it is time for the sheep to mate, the adult male rams run toward each other and hit each other with their horns.  This makes a loud noise.  The rams' skulls are thick and strong.

Bighorn sheep live up to 14 years.

Predators

Golden eagles, mountain lions, bears, Canada lynxes, and coyotes eat bighorn sheep. Bighorns can also die when lungworm parasites give them pneumonia.

History

The bighorn sheep came from Siberia. They crossed to North America over the Bering land bridge. The population grew in the millions.

Native Americans used bighorn sheep for food and made things out of their skins. It became part of the mythology of many groups of Native Americans.

By 1900, the population got smaller to several thousands. Almost all the bighorn sheep in the Rocky Mountains died in the 1800s and early 1900s.  Hunters killed them for meat and horns.  Bighorn sheep caught diseases from ranch sheep. Many organizations, including the Boy Scouts of America, have helped increase the population.

 References 

 Other websites 

U.S. Fish & Wildlife Service Species Profile 
Greater Yellowstone Resource Guide - Bighorn Sheep 
Desert Bighorn Sheep Facts  California Department of Fish and Game

Category:Caprids
Category:Mammals of North America