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Common name: Plains bison

Scientific name: Bison bison

Other names: Buffalo

Identification: 5-6 feet (1.5-1.8 m) tall, 800-2,000 lbs. (363-908 kg), dark brown, large head, high hump shoulders, long shaggy hair on front legs.

Habitat: Open plains, grasslands, park woodlands.

Food: Grass.

Reproduction: Breeding season is July-August. Gestation period is 9 months. Give birth to one calf in spring. Breeding age begins at 2 or 3 years old.

Behavior: Bison can be found in herds or alone. Herd social structure is complex and always changing. In the winter months, bison form matriarchal bands (cows and juveniles) and bachelor bands (3+ yr old bulls). A calving cow may remove herself from the herd or stay on the edge of the herd. Spring is when yearlings are weaned from maternal care and temporary yearling bands form. New mothers form nursery bands and mothers are fiercely protective of calves. Short term spinster bands consist of the barren and older cows. In summer the matriarchal bands come together into the cow-calf herd and when the bachelor herds join it is then called a breeding congregation. Rutting bulls can be quite active and engage in pushing, goring and fights. Breeding season is typically July-August and then the breeding congregation tends to split up. Wallowing, when a bison rolls on bare patches of dirt, is used for dust baths to protect from insects. Historically the large herds were migratory.

Conservation status: Tens of millions bison once occurred in North America but overhunting reduced them down to less than 2,000 animals by 1903. Conservation efforts on private and public lands have saved the bison from extinction. Today large public herds exist in places like Yellowstone National Park, Badlands National Park, Elk Island National Park, National Bison Range, Custer State Park, Wind Cave National Park and other areas. Several tribes also have bison populations. Many private ranches also have bison including lands owned by Ted Turner.


Recommended resources:

Portraits of the Bison by Wes Olson. 2005. The University of Alberta Press.
American bison: a natural history by Dale Lott. 2003. University of California Press.
Buffalo for the Broken Heart: Restoring Life to a Black Hills Ranch by Dan O'Brien. 2002. Random House.

PWR Footage of Plains bison: