American bison
The biggest land animal in North America, a shaggy grazer of the plains you can watch cross the road in Yellowstone.
American bison at a glance
Bison bison BY-sun; Bison bison is BY-sun BY-sun
- Type
- Mammal · bovine
- Diet
- Herbivore
- Size
- A big bull stands taller at the shoulder than a grown-up (about 6 feet) and can weigh as much as a small car (up to 2,000 pounds / 900 kg). Females are about half that weight.
- Lifespan
- Around 12 to 15 years in the wild, and a few live as long as 20 years.
- Conservation
- Near Threatened
Eats grasses, sedges, a few leafy plants
Bison graze most of the day, swinging their big heads low to tear off grass and sedge. More than 90% of what they eat is grass and grass-like plants, and in winter they sweep snow aside with their heads to reach it.
Should you worry?
Bison look slow and calm, but they are not tame and they hurt more people in Yellowstone than any other animal. They can run three times faster than you and turn fast. The rule is easy: stay at least 25 yards away (about two school buses), never walk toward one for a photo, and if it lifts its tail or paws the ground, back away.
A bison is the biggest animal that walks on land in North America, and up close it is bigger than it looks from the car. A bull can weigh as much as a small car and still run three times faster than you can. That is why the road in Yellowstone sometimes stops for a herd: the front of the group steps onto the pavement, and every car waits until the last calf has crossed.
Most of the day a bison does one thing: eat grass. It swings its heavy head low and tears at the ground, and in winter it sweeps the snow aside with that same head to reach the grass underneath. The hump on its shoulders is muscle built for the swinging.
There were once so many bison that a single herd could take days to pass. By the 1880s almost all of them were gone, down to a few hundred. Every wild bison you see today comes from those survivors, which is a strange thing to hold in your head while you sit in the car and wait for a two-thousand-pound animal to make up its mind about the road.
Did you know?
- A bison can run about 35 miles an hour and jump a fence about 5 feet high, which is surprising for an animal the size of a car.
- Bison were once so many, around 30 million, that herds took days to pass. By the 1880s hunting had left only a few hundred, and every wild herd today comes from those survivors.
- In 2016 the bison became the official national mammal of the United States, the animal version of the bald eagle.
Common questions
Are bison dangerous to kids?
They can be. Bison are wild and quick to charge if they feel crowded. Stay at least 25 yards back, keep the car between you and the animal when you can, and never try to touch or feed one.
Is a bison the same as a buffalo?
People call them buffalo, but true buffalo live in Africa and Asia. Our animal is really a bison. Both names get used, but bison is the correct one.
What do bison eat?
Almost all grass and grass-like plants. They spend most of the day grazing, even pushing snow away with their heads to reach the grass underneath.
How fast can a bison run?
About 35 miles an hour, faster than any person can run. That is why rangers ask you to keep your distance.