American Bison
Bison bison

Massive and thick-coated, bison were once the icons of North America’s Great Plains. They are the largest land animals on the continent. They were also once the most abundant, with an estimated 30 to 60 million before European settlement.

What They Eat
Bison eat mainly grasses and sedges—roughly 15 pounds per animal per day.

Where They Live
Bison roam wide-open prairies. The animals also inhabited savannas and forests in their heyday. The bison and the prairie benefit from each other, with the plants providing food for bison, and the bison’s grazing, trampling, and defecating helping keep the prairie ecosystem healthy.

What They Do
Bison spend their mornings eating and their afternoons chewing cud. Their thick fur helps these animals survive the bone-chilling cold of prairie winters.

How They’re Doing
Bison were hunted to near oblivion in the 1800s, with populations down to less than 600 before protective measures were put into place. Today, with more than 50,000 animals in the wild and on farms, the bison is considered a conservation success story.

American Bison

• Bison grunt periodically to communicate and keep contact with the rest of the herd. They bellow aggressively when challenging another animal.
• In winter bison clear snow from their grazing area by sweeping their massive heads from side to side.
• Wolves and grizzly bears are natural predators of bison.
• Today bison are raised in herds to provide low-cholesterol meat.

Conservation Notes

Bison are a conservation success story. They were hunted and slaughtered to near extinction in the early 1800s, but brought back to healthy numbers through protection and captive management. One of the first herds established for captive reproduction was on the Smithsonian grounds in Washington, D.C. The American Bison Society, organized at the Bronx Zoo in 1905, gathered and bred animals to stock government preserves in Oklahoma and South Dakota. This was the first reintroduction of animals from zoos back into the wild.

American Bison

Range and Habitat
Four subspecies of bison once roamed North America from Alaska to Mexico. The pale bison (Colorado) and eastern bison (Maryland, Pennsylvania, and Virginia) are now extinct. The wood bison (Canadian woodlands) is very rare. The plains bison, which favored the grasslands, is the one displayed at the Minnesota Zoo. Before Europeans arrived in North America, bison formed what were probably the largest aggregations of large land animals on Earth—an estimated 30–60 million animals. They ranged in huge herds over most of the continent, mostly on the plains, but as far east as New York and New England, and as far south as Georgia.

Description
These bulky relatives of domestic cattle are the largest land animals in North America. Males average 9–12 feet long and 6 feet tall at the shoulder. They usually weigh about 1 ton, but 3,000-pound bison have been recorded. Females are a bit smaller at 7–8 feet long and 5 feet at the shoulder. Both males and females have horns.

Habits and Adaptations
Bison are usually found in herds, though old bulls are often loners. Most often they are peaceful grazers, except during mating season. However, all bison are unpredictable and may attack for no apparent reason. Bison wallow or roll in mud or dust to scratch and to protect themselves from biting insects. They most often travel at a walk, but can travel very fast over rough terrain for extremely long distances. Some have been clocked at 35 mph.

Diet
Bison eat a variety of grasses and other plants. Like domestic cattle, they are ruminant (cud-chewing) animals. They have a four-chambered stomach. When they eat, the food goes to the first stomach. Later, they regurgitate the food and chew it. This allows them to eat quickly in the open where predators may be lurking, then process the food later. Bison usually feed in the morning, then lie and chew their cud during the hot afternoon hours.

Life History
Bison breed in August and September. Although most bulls reach sexual maturity at age 3, they must fight to achieve dominance before they can mate. Most dominant bulls are 4–8 years old. Cows usually begin breeding after their third year and bear a calf each year. Gestation is 9½ months, and calves are born usually in late April and May. Bison live about 20 years in captivity and 15 years in the wild.

Relationship With Humans
In their heyday, bison were the superstores of the prairie. Plains Indians ate the meat. They used the skins for clothing, shoes, boats, bedding, blankets, tipis, and drums. They turned bison bones into knives and other tools. The stomach was used as a cooking pot. Horns were used for arrow tips, and the hooves produced glue. Bison dung was burned as fuel. Today, some bison are raised on farms and ranches as a source of low-cholesterol meat.