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American Bison

Bison bison

About American Bison


Historically found throughout grasslands and open savannas of North America. Today, their population is distributed throughout western North America.


Bison are year-round grazers and primarily eat grasses, but also eat flowering plants, lichens, and woody plant leaves.

Family Life

Social animals arranged in groups according to age and sex. Cow groups are mostly comprised of females and males under three years old, with a few older males. Males are either solitary or live in groups of 30 or more. Females have one calf per season, which they nurse for 7 – 8 months. The female fully weans the calf off of her milk by the end of the first year.

Conservation Status

The conservation status of the American Bison is classified as near threatened.
Near threatened graphic


  • Due to their large size, adult bison are relatively safe from predators. However, elderly and sick members of the herd can be prey to mountain lions, wolves, and humans.
  • The destruction of the bison population over time is attributed to several political and economic issues dating back to the 19th century. The United States government killed bison to destroy the livelihood of Plains Indians. Since then, the bison species has struggled to thrive.

Facts about American Bison

  • Class:
    Mammalia (mammals)
  • Order:
    Cetartiodactyla (even-toed ungulates)
  • Family:
    Bovidae (antelope, cattle, goats, etc.)
  • Genus:
    Bison (bison)
  • Species:
    Bison bison (bison)
  • Life Span:
    15 – 20 years (wild) / up to 40 years (zoo)
  • Size:
    Male: 9 – 12.5 feet (2.7 – 3.8 m) / female: 7 – 10 feet (2.2 – 3.2 m)
  • Height:
    Male: 5.5 – 6.5 feet (1.5 m) tall / female: 5 feet (1.5 m)
  • Weight:
    1,800 – 2,400 pounds (816 – 1088 kg)

Fun Facts

  • In winter, bison use their heads as shovels to clear snow by sweeping side to side. That’s one way to do it!
  • Bison are a keystone species, meaning the ecosystem largely depends on their actions. They impact the plants and animals around them by grazing and dust baths.
  • Bison were nearly hunted to extinction — by 1860, the estimated population of 60 million bison was down to less than 1,000!
  • In the spring, bison shed their heavy coats and roll around on the ground to help loosen the hair.
  • Buffalo comes from the French word for beef “boeuf”.

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