Facts About Bison

Buffalo and bison are not the same animal. Typically, the big fluffy animals that people call buffalo are actually bison, while true buffalo look more like large bulls. The two are related though. Bison and buffalo are bovines (a subfamily of bovids), but bison are in a different genus from buffalo. Other relatives include antelopes, cattle, goats and sheep. 

There are two different species of bison: the American bison and the European bison. The American bison became the official national mammal of the United States when President Barack Obama signed the National Bison Legacy Act into law on May 9, 2016, according to the U.S. Department of the Interior. 

Size

The American bison is the largest mammal in North America. It grows to 7 to 11.5 feet (2.1 meters to 3.5) long from head to rump, and its tail adds an extra 20 to 23.5 inches. They weigh 930 to 2,200 lbs. (422 to 998 kilograms).

The European bison is the largest herbivore in Europe, according to Encyclopedia Britannica. It is around 9.5 feet (3 m) long. While it’s around the same length as the American bison, it is typically heavier. It weighs a whopping 1,762 to 2,203 lbs. (800 to 1,000 kg).

Wood bison, with a calf.

(Image credit: Alaska Department of Fish and Game)

Habitat

The American bison can be found in the United States, Canada and Mexico, mostly in conservation areas, preserves or farms. The European bison was once found throughout Europe. Now it is found in Poland, Belarus, Lithuania, Russia, Ukraine and Slovakia.

Habits 

Bison are social creatures and live in groups called herds. A herd usually contains females and their offspring. Males will either live near a herd of females or will belong to a herd that consists of other males. 

Bison are migratory animals. Herds migrate south in winter and move back north in the spring.

These large animals mate around August of every year. The males tend to fight and bellow for the choice females, but research shows that females may prefer the quieter males. “We were expecting to find that the bigger, stronger guys — the high-quality males — would have the loudest bellows, because they can handle the costs of it,” said Megan Wyman, a graduate student in geography at University of California, Davis and the lead author of the study. “But instead, we found the opposite.” 

Another surprising finding is that sometimes the males are more interested in other males. More than 55 percent of mounting tends to be young males with the same gender. [Related: Shh! Quiet Bison Get More Sex]

The modern European bison (also called wisent or Bison bonasus) from the Białowieża Forest in Poland.

(Image credit: Rafał Kowalczyk)

Diet

Buffalo are herbivores, which means they only eat vegetation. Typically, grass and herbs are on the menu, but they will also eat leaves and twigs. 

Offspring

Births usually occur between March and May. A female, called a cow, will give birth after a gestation period of nine months. Usually, she will give birth to only one young at a time, though twins have been recorded. 

A baby bison is called a calf. Calves are born big. American bison calves weigh a massive 30 to 70 lbs. (14 to 32 kg) at birth, according to the U.S. Department of Interior.

A calf is protected not only by its mother, but also by the whole herd. They are weaned at 7 to 13 months and typically become sexually mature at 2 to 3 years of age. Adult bison live around 14 to 24 years in the wild.

Classification/taxonomy 

Here is the classification of bison, according to the Integrated Taxonomic Information System (ITIS):

Kingdom: Animalia Subkingdom: Bilateria Infrakingdom: Deuterostomia Phylum: Chordata Subphylum: Vertebrata Infraphylum: Gnathostomata Superclass: Tetrapoda Class: Mammalia Subclass: Theria Infraclass: Eutheria Order: Artiodactyla Family: Bovidae Subfamily: Bovinae Genus: Bison Species: 

• Bison bison (American bison)
• Bison bonasus (European bison)

Conservation status

Millions of bison roamed North America in prehistoric times, according to the U.S. Department of the Interior. Many Native American tribes depended on the bison for food, clothing and shelter. But by the late 1800s, only a few hundred bison were left in the United States. As European settlers pushed west, they reduced the animal’s habitat and hunted them to near extinction. 

Today, while not endangered, bison are not doing very well. The American bison is listed as near threatened by the International Union for Conservation of Nature (IUCN) Red List. This is due to the bison’s dependence on conservation programs to survive. The American bison has only 19,000 total plains bison in 54 conservation herds and 11,000 total wood bison in 11 conservation herds, according to IUCN. There are 500,000 bison living on preserves and ranches, according to National Geographic (opens in new tab).

The European bison is listed as vulnerable by the IUCN. The organization believes that there may be less than 1,000 mature European bison in existence.

Other facts

Both males and female bison have horns.

Bison are typically brown in color. Rarely, a white bison is born. These bison were worshiped by Native Americans. 

Bison are fast runners. They can run up to 40 mph (65 k/mh), according to Encyclopedia Britannica. 

When a bison’s tail sticks straight up that means the animal is angry.

Additional resources