Are Bison Dangerous? Speed, Charges and Safe Distances

Why bison injure people

Bison are not predators and do not hunt people. Like most large wild animals, they simply defend their personal space. The trouble is that bison look calm and slow as they graze, so visitors often walk up to take photos, sometimes to within a few meters.

To a bison, a person who keeps coming closer is a threat. It may respond by charging and hooking with its horns, or by tossing a person into the air with its head. Most injuries are gorings, broken bones and bruises. A review of bison injuries in Yellowstone found that many of the people hurt had walked up close to the animal, often to take photographs.

How fast can a bison run?

The American bison is much faster than it looks. Bison can gallop at about 55 km/h (35 mph), roughly twice as fast as a fit adult can sprint, and they reach top speed in a few strides. They can also pivot quickly, jump obstacles about 1.5 m (5 ft) high and swim across rivers.

This combination of speed, agility and sheer weight is why a charge is so hard to escape. A person standing 10 m (33 ft) away from a bison has well under a second before an animal at full speed covers the gap. To see how bison compare with other runners, see our list of the fastest animals.

How often do bison hurt people?

Bison injuries are uncommon compared with the millions of visitors to bison parks, but they happen almost every year. Between 1980 and 1999, bison charged and injured 79 people in Yellowstone, more than three times the 24 people injured by bears in the same period. In recent years, the park has often recorded one or more bison injuries in a single summer, and each one usually makes the news.

Deaths are rare. Bison killed a visitor in Yellowstone in 1983, and fatal incidents have occurred in other parks and on ranches. Most serious injuries in Yellowstone involve people who were well inside the park’s minimum distance.

Warning signs of an agitated bison

Bison often show that they are uneasy before they charge, although they can also charge with no obvious warning. Signs include:

• Raised tail. A tail held straight up or crooked can mean the animal is agitated and ready to run or charge. (It can also mean it is about to defecate, but either way it is time to back away.)
• Head facing you. A bison that stops grazing, raises its head and stares at you is paying close attention.
• Pawing, snorting and head bobbing. These are signs of stress or challenge, especially in bulls.
• Bellowing and wallowing. During the rut, bulls roar and roll in dust to show their strength, and they are much more excitable.
• Short false charges. A bison may run a few steps toward you and stop. Treat this as a final warning.

When are bison most dangerous?

Two seasons carry extra risk. During the rut, from about late June to September with a peak in July and August, bulls fight each other and can be quick to charge anything that gets in the way. In spring, from about April to June, cows with young calves are protective and may charge people who come between them and their calves.

Bison are also dangerous on roads. Herds often walk along or across park roads, causing “bison jams”, and a bison hit by a car can cause a serious crash. Driving slowly, especially at dawn, dusk and night, protects both people and animals.

Safe distances and how to stay safe

Yellowstone requires visitors to stay at least 25 yards (23 m) from bison, elk and other large animals, and at least 100 yards (91 m) from bears and wolves. Other parks have similar rules. A simple test is to hold your arm straight out and raise your thumb: if the bison does not fit behind your thumb, you are probably too close.

• Never approach, follow, feed, touch or pose for a selfie next to a bison.
• If a bison walks toward you on a trail or boardwalk, turn around or step well aside and give it room.
• Use binoculars or a telephoto lens instead of walking closer.
• Keep children close and dogs leashed and away from wildlife.
• Stay in your vehicle when a herd crosses the road, and do not honk or nudge the animals.
• Never come between a cow and her calf.

If anyone is hurt by a bison or any other wild animal, seek emergency medical help immediately: call 911 in the US or Canada.

Bison compared with other large animals

Bison are only one of several large animals that cause injuries in North American parks. Elk can also charge in the autumn rut and the spring calving season, and moose are often considered among the most dangerous animals in the North because people underestimate them; see are moose dangerous? The common rule is the same for all of them: give big animals plenty of space, and they will almost always leave you alone.