American Bison

American Bison

[ Bison bison ]

Quick Facts

BODY LENGTH: 7 to 11 feet
BODY HEIGHT: up to 6 1/2 feet
WEIGHT: 770 to 2200 hundred pounds
WILD DIET: grasses, small plants, and shrubs
herbivore grain pellets, brome hay, and carrots
small pockets in western and northern North America
HABITAT: plains and prairies

An American Icon

Bison Body Bulk
There’s no getting around it. Bison are big animals, especially the males. A full grown adult male can tip the scales at over one ton!  With a broad forehead and large head, short, curved horns, pronounced shoulder hump, straggly beard, and shaggy brown coat, an American bison isn’t to be messed with. In fact, during mating season, males engage in head-to-head fierce battles for breeding rights.  Female bison often incite males by galloping about them to instigate competition. To top it all off, despite all the body bulk, bison are quite agile and can run at speeds over 30 miles per hour.
Roaming Through History
In the late 1700’s, nearly 50 million bison once roamed much of North America – from Canada’s far northwest, south to Mexico, and as far east as the Appalachian Mountains.  During this era, massive bison herds would migrate hundreds of miles every year along trails, which eventually became the paths used for railroad tracks. Today, the American bison is nearly extinct in the wild with only a handful of herds remaining on their original range. Most bison are managed as livestock or captive herds, the two largest herds residing in Yellowstone National Park and Wood Buffalo National Park. 
Natural Grazers
Bison that graze vast prairie acreages help restore the Great Plains. Unlike domestic livestock, bison graze in ways that help maintain the prairie ecosystem, leaving behind pockets of untouched vegetation that serve as habitat for other prairie-dwellers. Many people are working to create large areas where wild bison can once again roam, creating this important ecosystem. You can be a part of the solution and help restore the prairie ecosystem, one bite at a time.  Next time you’re at a restaurant or at the grocery store, purchase prairie-fed, free-range bison meat.  This single decision not only helps conserve bison and prairie, but Great Plains wildlife.


What's in a Bison Name?

While true buffalo are the Cape buffalo of Africa or the water buffalo of Asia, the American Bison has been called "Buffalo" for so long that we now use the names interchangeably. The bison's only relative are remnants of another bison species called the wisent, which survive in small numbers on reserves in Europe.

American Bison at Brookfield Zoo
Great Bear Wilderness is home to our bison herd. The lone male of the herd, Ron, is easy to pick out, as he’s the biggest! They have access to a prairie pasture where they can graze on native Illinois plants and wallow in mud holes. Remember to look for our bison on the overpass of Great Bear Wilderness and prepare to stand nose-to-nose with them in the exhibit’s tunnel.

Get Involved

Conservation Fund of the Chicago Zoological Society