American Bison (Buffalo)

Meet the American Bison

The American bison takes the top prize for the largest land mammal in North America. Adult males weigh in at up to 2,000 pounds and stand as tall as six feet high at the shoulder.

These titans of North America are grazers, matriarchal-led family groups ranging from tens to thousands of buffalo. As they move across the prairie, they selectively focus on the grasses and sedges avoiding most of the forbs and legumes which helps balance the floristic competition. They sometimes wallow, which among many benefits helps mitigate biting insects and is also a social behavior thought to be a sign of contentment. These wallows create shallow depressions in the dense prairie which provide microhabitats to insects and amphibians among others to complete their reproductive cycles.

Adult males reach sexual maturity at six years old and females at three years old. They mate once each year beginning in July and lasting up to September. During the mating season, also called the rut, bulls (males) will fight aggressively by ramming their heads together and charging at one another for a chance to mate with a cow (female).

After a nine-month gestation period, cows will give birth to a single calf each spring. You can typically see mothers with young calves beginning in April.

It’s worth noting here that female bison weigh up to 1,000 pounds and run just as fast as the males at 40 miles per hour.

Bison are very protective of their young and as a group do their best to protect them from any dangers. When visiting a TNC preserve—or any preserve—where bison are present, it’s best to give them the space and respect they deserve, for your safety and for theirs. 

Wait…Are they bison or buffalo? 

Yes! Both terms have important scientific and historical meanings and use, and both continue to be used today to refer to the nation’s official mammal. There are also hundreds of words from Indigenous languages that have been used for thousands of years. Words like: “tatanka” or “pte” in Lakota or “yanasi” in Cherokee.

Genetically speaking, the American bison is not akin to either the water buffalo of Asia or the Cape buffalo of Africa. The American bison are found only in North America and certain parts of Europe.

Oceans apart in their range, the physical appearance of the American bison is vastly different from water buffalo and Cape buffalo. Developing on different continents means they encountered different conditions including climate, which influenced the evolution of their bodies and behavior.

Protecting the American Bison 

Millions of bison once lived and traveled across huge sections of the United States. You could see these icons of the prairie from Canada all the way south to Mexico and even as far east and west as the coasts.

But as American settlers developed and expanded, the U.S. government encouraged settlers to slaughter millions of these animals, bringing bison and the Indigenous communities that relied upon the herds to near extinction in the early 20^th century.

At the end of this brutality, tribal communities were decimated, and less than 1,000 free-roaming bison remained in the world.

Today, about 500,000 bison live in the U.S. and can be found in all 50 states. However, most of these bison are privately owned and raised as livestock. Only a small fraction of this number includes bison who are living in conservation herds and even much less than that are bison who are roaming on large landscapes. There are no truly free-roaming bison left in North America. Fortunately.

The Nature Conservancy collectively is one of the largest bison producers with over 6,000 bison living on 12 preserves we own and manage in the United States.  

Find a Bison Herd Near You