Bison Facts & Figures

Bison calf and cow standing in grass

NPS photo

Learn the facts about bison, named America's national mammal in 2016.

  • Class: Mammalia
  • Order: Artiodactyla (same as deer, sheep, pronghorn)
  • Family: Bovidae (true horns, not branched, on both sexes, cattle, sheep, goat, musk ox)
  • Genus: Bison
  • Species: bison
  • Subspecies: athabascae (woods); bison (plains)
  • Name/History: In the late 1800s, bison almost became extinct. They were saved by the American Bison Society. Often called buffalo by early scientists who thought they were related to the Africa/Asian water buffaloes. French explorers also called the animals "les boeff"—the cattle.
  • Weight/Height: Male - 2000 lbs, 5.5–6 ft; Female - 1000 lbs, 4.5–5.5 ft; Calf - 30–70 lbs, 2.5 ft
  • Rut: June–September (one bull forms a temporary "tending bond" with one cow at a time)
  • Gestation: 9.5 months
  • Birth: April–June (reddish, brown fur, no conspicuous hump)
  • Number of young: Usually 1
  • Age: 12–15 years
  • Habitat/Range: At one time, bison roamed North America from Alaska to northern Mexico and western California to western New York.
  • Food: Grasses, browse
  • Predators: Occasionally grizzly, humans, extinct prairie wolf
  • Disease: Brucellosis, tuberculosis
  • Communication: Grunts/snorts between cow-calf, roar by bulls during rut
  • Behavior/Characteristics: Generally cow/calves in herd together, bulls alone or in small bull herd except during the rut

Last updated: December 29, 2016