The Most Dangerous Bear and 9 Others to Give a Wide Berth

The polar bear is considered the most dangerous bear species due to its sheer size, power and unpredictable nature. As the largest land carnivore, adult male polar bears can weigh up to 1,500 pounds (680.4).

Polar bears are native to the Arctic and are known for preying on local seals with their incredibly sharp teeth. It is extremely unlikely for a human to fall victim to a polar bear attack, but the creature's incredible strength means that you wouldn't want to provoke one, either.

The bears generally stick to colder, more remote geography closer to the North Pole, but they may sometimes wander into more populated human cities in Alaska and Canada. Their hunting instincts can be triggered in areas where food is scarce, leading to polar bear attacks.

They are also highly territorial, and with a lack of natural predators, polar bears don't fear humans, making them especially dangerous if encountered in the wild.

Coming in at No. 2, the grizzly is a subspecies of the North American brown bear and is notorious for its aggressive behavior. Grizzly bears are responsible for the most bear attacks in North America, especially in areas like Alaska and western Canada.

Weighing up to 800 pounds (362.9 kg), these bears are highly protective of their cubs and territory. Grizzlies have an unpredictable nature, and their speed and strength make any encounter potentially dangerous.

In the event of a grizzly bear attack or conflict with other brown bears, the National Park Service recommends that you lay down on the ground as motionless as possible to convince the animal that you are not a threat to it or its cubs.

You will not be able to outrun or overpower hulking grizzly bears. Wait several minutes for the grizzly bears to leave the area before trying to get up and move around.

The Kodiak bear, a subspecies of the brown bear, is native to the Kodiak Archipelago in Alaska.

These bears are massive, often reaching over 1,400 pounds (635 kg), and while they are generally not aggressive toward humans, their sheer size and strength make them one of the most dangerous bears if provoked.

While Kodiak bears rarely hunt humans, they will defend themselves fiercely if threatened.

Despite the cute name, sloth bears are known for being particularly aggressive, especially toward humans. Found in India and Sri Lanka, these bears have long, sharp claws and a powerful bite. Unlike most other bears, sloth bears are known to attack humans unprovoked, often causing serious injuries.

Sloth bear attacks are among the most frequent in the world, largely because they live in areas with higher human populations. Sloth bears are thought to have developed this aggressive behavior as a defense mechanism against Asian tigers, which tend to prowl around the bear's natural habitats.

The Eurasian brown bear is another brown bear species, found across Europe and parts of Asia. While generally shy around humans, these bears can become dangerous if startled or provoked. Their large size and strong jaws mean that any encounter could be deadly.

Most attacks happen when Eurasian brown bears feel threatened or surprised, making them one of the more unpredictable bears in the wild.

The Far Eastern brown bear, or Kamchatka brown bear, is native to Siberia and parts of Japan. The bear is similar to its Eurasian counterpart but can be even more aggressive. These bears are larger and more carnivorous than other brown bears, and they've been known to hunt humans in rare cases.

Their habitat overlaps with human settlements, increasing the likelihood of attacks, making them one of the most dangerous bears in the world.

Though they are one of the most common bear species in North America, the American black bear is also one of the more timid bear species. That said, these bears can still be dangerous, especially when food is scarce or when a mother is protecting her cubs.

While black bears are responsible for fewer fatalities than other bears, their opportunistic nature and frequent interactions with humans mean they can become aggressive, especially when cornered or startled.

Unlike grizzlies and other brown bear species, it is recommended to fight back in the case of a black bear attack. Be loud, swing your arms and hit the bear with branches or anything at your disposal in order to scare the animal off.

If all else fails, aim a can of bear spray at its face to send the creature packing.

Native to the Andes Mountains in South America, the spectacled bear is typically more shy and elusive than other bear species. While they aren't known to attack humans frequently, they can become aggressive if they feel threatened.

Spectacled bears are much smaller than brown bears or polar bears, but their sharp claws and strong jaws still make them dangerous in close encounters.

The sun bear, found in Southeast Asia, is the smallest of all bear species but don't let its size fool you. Sun bears can be surprisingly aggressive, especially if they feel cornered.

These bears have long claws and strong teeth, which they use to defend themselves if necessary. Though they are less likely to encounter humans than other bears, their aggression makes them dangerous when they do.

The giant panda may seem like a gentle giant with its bamboo-munching habits, but it still belongs to the bear family and can become aggressive if threatened.

While pandas are known for being solitary and peaceful, their size and strength make them capable of causing harm. However, attacks on humans are extremely rare, placing them low on the list of dangerous bears.

We created this article in conjunction with AI technology, then made sure it was edited and fact-checked by a HowStuffWorks editor.