ORDER

Artiodactyla (even toed ungulates)

FAMILY

Bovidae (antelope, cattle, gazelles, goats, sheep and relatives)

HABITAT AND RANGE

Varied; primarily plains, prairies and river valleys and sometimes forests. The American Bison once roamed most of Canada, the United States and parts of Mexico. Wild herds are only found in wildlife refuges and national parks such as the National Bison Range of Flathead Valley in Montana and Yellowstone National Park in Wyoming.

IDENTIFICATION

Bison are the largest terrestrial animals in North America. Males can stand up to 6 feet tall from hoof to shoulder and weigh between 1000 and 2000 lbs. Females stand about 5 feet tall and weigh between 800 and 1000 lbs. They have dark brown shaggy hair with large hooves and a shaggy mane and beard. They have massive heads with muscular necks, humped shoulders with short legs.

DIET

American Bison are grazers. They primarily feed on prairie grasses, sedges and forbs but may sometimes feed on berries, lichens and horsetails. Their heads hang low and are supported by massive muscles so that during the winter they can sweep their heads side to side to clear snow to access the vegetation underneath.

REPRODUCTION AND LIFESPAN

Female Bison reach sexual maturity between the ages of 2 and 3 while males do not reach maturity until they are at least 6 years of age. Mating season begins in June and can extend until September. Male herds will move into female herds and the males will chose a female and ‘tend’ to her. During ‘tending’ (which can last from several minutes to several days) the male will remain at the cow’s side and will battle any male who comes too close. One, occasionally two, calves are born after about 9 months of gestation. Newborn calves can stand and nurse within 30 minutes of birth and walk within hours. The mother and calf will rejoin the herd after 1-2 days. Claves are weaned after about 7 months.

NOTES

All members of the Bovidae family have horns made of keratin over a bony core which are never shed and have four chambered stomachs to digest the plants they feed on. Males and females live in separate herds (except during breeding) with a dominant individual. Herds number between 4-20 individuals. Since Native Americans were heavily reliant on the buffalo herds for food and clothing, the US Government, in order to subdue hostile tribes, advocated extensive extermination of bison herds in the 1830’s. When the railroads were established, passengers were given rifles and encouraged to shoot bison from the trains. Before western expansion, bison were estimated to number between 30-70 million from Canada down to Mexico. Due to their extermination, they numbered as few as 1000 individuals by 1900. Due to rescue and conservation efforts they now number 65,000 but remain on the endangered species list. When frightened, bison herds often stampede and can gallop at speeds up to 32 mph.