Are Bears Dangerous to Humans? Attack Risk and Bear Safety

How common are bear attacks?

Bear attacks get a lot of attention because they are dramatic, not because they are frequent. The Canadian biologist Stephen Herrero, who studied bear attacks for decades, found that in the 1990s bears killed about three people a year in the United States and Canada combined. Over the same period, domestic dogs killed far more people each year.

A 2019 study led by Giulia Bombieri reviewed brown bear attacks worldwide between 2000 and 2015 and counted 664 attacks on people, of which 95 were fatal. Most victims were taking part in outdoor activities such as hiking or hunting, and the number of attacks is small compared with the many millions of visits people make to bear country.

Grizzly and brown bears

Brown bears, including grizzlies, are large and powerful, and their attacks are more likely to cause serious injury than those of black bears. Most are defensive. The bear feels threatened, usually because a person has surprised it at close range, come between a mother and her cubs, or approached a carcass the bear is guarding. In North America, mothers with cubs have been involved in most fatal grizzly attacks.

Brown bears usually avoid people and leave when they hear them coming. Attacks are more likely on people moving quietly through thick cover, alone or in pairs, in late summer and autumn when bears are feeding intensely. In Europe, brown bears are generally shy; Scandinavia recorded only a handful of fatal attacks in the whole 20th century, although incidents have increased in some areas with dense bear populations, such as parts of Romania.

American black bears

American black bears are by far the most common bears in North America, with an estimated 750,000–950,000 animals, so people meet them most often. Most black bears are timid. When stressed they huff, slap the ground, pop their jaws or make a bluff charge, then retreat, and mother black bears usually send their cubs up a tree instead of attacking.

Serious attacks are rare. A review published in 2011 found 63 people killed by wild black bears in 59 incidents in Canada and the United States between 1900 and 2009. Unusually, 88% of those fatal attacks appeared to be predatory rather than defensive, and most were by adult males in remote areas. Far more common are black bears raiding garbage, bird feeders and campsites, which is why secure food storage matters so much.

Polar bears

Polar bears are the largest bears and the most likely to view a person as potential prey, especially hungry young males. Still, attacks are rare because few people live or travel in polar bear country. A 2017 study counted 73 polar bear attacks from 1870 to 2014 across Canada, the United States, Greenland, Norway and Russia, causing 20 deaths and 63 injuries.

Most of the attacking bears were in poor body condition, and the researchers linked a recent rise in incidents to longer ice-free seasons, which keep bears on land and hungry for longer. As the Arctic warms, communities in places such as Churchill in Canada and Svalbard in Norway use patrols, warning systems and secure food storage to keep people and bears apart.

Why do bears attack?

Researchers group bear attacks into a few main types:

• Defensive attacks: the bear is startled at close range, is defending cubs, or is guarding a food source. This is the most common type for grizzlies.
• Food-conditioned bears: bears that have eaten garbage, pet food or camp food lose their fear of people and may approach aggressively.
• Predatory attacks: rare cases in which a bear treats a person as prey, seen mainly in some black bear and polar bear incidents.
• Provoked incidents: people approaching bears for photos, feeding them or entering zoo enclosures.

How to avoid bear encounters

The best protection is not meeting a bear at close range in the first place. Wildlife agencies in North America and Europe recommend:

• Make noise on the trail, especially near streams, in thick brush and around blind corners.
• Hike in groups and in daylight, and keep children close and dogs on a leash.
• Never approach, follow or feed a bear, and keep well back: Yellowstone National Park, for example, requires at least 100 yards (about 90 m).
• Store food, trash and scented items in bear-proof containers or as the campground directs.
• Leave the area if you see a carcass or fresh signs of bears.
• If you see a bear, do not run. Stay calm, give it space and move away slowly while watching it.

Advice on what to do if a bear comes close differs between species and situations, so read the guidance of the park or wildlife agency before you visit, and many North American parks advise carrying bear spray. If anyone is injured by a wild animal, seek emergency medical help immediately: call 911 in the US and Canada, 112 in the EU or 999 in the UK.

Myths and facts

• Myth: black bears are harmless. Fact: they are usually timid, but a small number of attacks have been fatal, so all bears deserve respect.
• Myth: bears hunt people. Fact: most attacks are defensive; predatory attacks are rare.
• Myth: you can outrun a bear. Fact: bears can sprint at about 40–48 km/h (25–30 mph); see how fast can a bear run?