Polar bears are classed as marine mammals and are excellent swimmers, but there isn’t much information on other bear species that can swim.
Polar bears are excellent swimmers and can swim many miles to reach new ice sheets. Brown bears and black bears can swim but typically only do this to find food. Polar bears can swim faster than humans, although a race between a black bear, a brown bear, and a human would be close.
North American bears include the brown bear Ursus arctos, commonly called the grizzly bear, and the black bear Ursus americanus, the most widely distributed of all bear species. These two bears are primarily land-bound.
However, a very close relative of the brown bear, the polar bear Ursus maritimus, found in the arctic circle, is considered both a land and a water mammal.
Can Black Bears Swim?
Black bears live terrestrially and, having a primarily herbivorous diet, swim only when needed, such as during the popular salmon spawning season. The cubs of black bears cannot swim until they reach about 13 kg.
Black bears enter the water while fishing for salmon on their way to spawning upstream, but the best fishing spots are in the shallow waters where no swimming is required.
Black bears with cubs usually don’t go to the famous fishing spots, as their cubs may be at risk of danger from more giant, more dominant male bears. This consequently means that they may not be exposed to the opportunity of swimming until later in life.
Black bears are adequate swimmers, but they only swim short distances of several kilometers to get across a lake or from one island to another.
Bear cubs are not included in the seasonal salmon fishing events, as they may be at risk of death from other bears in a densely populated area.
Can Brown Bears Swim?
Brown bears can swim and propel themselves forward with the doggy paddle movement. They cannot swim long distances but can be seen swimming between islands in search of food.
Brown bears can swim well but get tired quickly, so they cannot swim long distances. Cubs are usually kept from popular salmon spawning areas as more significant, more dominant bears may attack and kill them.
The brown bears of the ABC islands of Southeast Alaska have often been seen swimming between the island’s channels. They do this as different islands vary in the available vegetation. According to the National Park Service of Katmai, black bears have also been known to swim for fun.
Can Polar Bears Swim?
Polar bears are classed as marine mammals partly due to their swimming time. Polar bears have several adaptations to travel long distances without stopping.
Their paws are webbed, which allows them to pull themselves through the water quickly and without expending as much energy.
A female swam for nine days with a small break in the middle, traveling 687 km (426 miles), and it is thought that longer distances will need to be traversed in the future due to climate change and the shrinking sea ice.
Polar bears also have a thick layer of fat called blubber, which helps keep them insulated when swimming long distances.
Polar bears are apex predators. Please find out how they hunt in this article I wrote.
How Do Bears Swim?
Bears have a similar body shape and physiology to dogs and swim using a doggy paddle. The doggy paddle stroke primarily uses the front limbs in a paddling motion, while the back legs are used very little.
Polar bears have adapted large paws, partially webbed to aid in propulsion through the water and stability while traversing the ice sheets.
In the form mentioned above, swimming is inefficient, and energy can be depleted quickly. Because of this, brown and black bears cannot swim long distances.
The black and brown bears are less efficient swimmers than the polar bear. Their habitats are much more land-based, and their diet consists mainly of plant materials, seasonal salmon, and sometimes fresh meat or carrion if the opportunity arises.
Polar bears are strictly carnivorous, feeding primarily on seals that use breaks in the ice for breathing or as exit holes. A polar bear may dive in and out of the water in an attempt at a sneak attack on a seal, or even, much less often, whales that use breaks in the ice as breathing holes.
A study conducted by Dutch researchers claimed that polar bear/brown bear hybrids, known as grolar bears, are better swimmers than brown bears but not as skilled as polar bears.
Why Do Bears Swim?
Polar bears spend most of their lives on sea ice hunting. In the summer, the sea ice begins to break apart, leaving large spaces between ice sheets. Polar bears need to travel between these ice sheets to continue hunting for seals, and swimming is the only way to do that. These ice sheets have become farther apart as the earth warms and more sea ice melts, increasing polar bears’ need to swim.
Brown and black bears only venture into the water for hunting purposes. One of their primary sources of food in the spring season is migrating salmon. The best place for fishing is in the stream’s shallow waters, so very little swimming is required.
Did you know that bears evolved from dog-sized animals? Find out more here
How Far Can Bears Swim?
Polar bears are considered marine mammals, as they spend much of their time at sea and have been known to swim hundreds of kilometers between ice sheets. One female polar bear was recorded swimming 687 kilometers over nine days with only a two-day rest.
Polar bears generally swim for up to 10 hours a day before resting. However, polar bears already have to travel further between ice sheets because of climate change.
Brown bears have been seen swimming across the canals between the ABC islands in Southeast Antarctica, some as far as 1.6km apart.
How Fast Can Bears Swim?
Very little research is available on the speed at which bears can swim. However, some sources, including the WWF, indicate that polar bears can swim about ten kph (6 mph.)
Whenever I have seen brown or black bears swim, I would describe them as swimming at their average walking pace.
Can You Outswim a Bear?
The average swimming speed for a human is about 3.2 kph (2 mph). However, Michael Phelps, an Olympian with 23 gold medals, has a record of 9.66 kph (6 mph).
Polar bears can swim at about ten kph (6 mph), so it is unlikely that even the fastest recorded swimmer on the planet could outswim a polar bear.
Brown and black bears usually swim at about the same speed they walk. It is unlikely that you would be able to outswim a black or brown bear, and impossible to outswim a polar bear.
Can Bear Cubs Swim?
Polar bears are classified as marine mammals, and their cubs can swim. The cubs learn from their mother and are ready to learn to swim at about 15 weeks of age. Because the energy is high, swimming vast distances is not viable for a young bear.
Shorter distances between ice sheets are much easier for a young cub to swim between. Polar bear cubs develop thick waterproof coats soon after hibernation is over.
Black and brown bear cubs cannot swim until they are around 13.6 kg (30 lbs), whereas polar bear cubs are usually about 18 kg (40 lbs.)
Want to find out if bears can climb trees? Find out here.
Polar Bears are the best swimmers out of the three species of bear in North America. They can swim great distances, and their physiological adaptations assist with their long journeys.
Polar bears are not particularly fast or energy efficient, but they can travel long distances. Their cubs learn to swim young and can swim longer distances than adult black or brown bears.
Ever wondered if you can outrun a bear? Find out in this article I have written here.
Can Giant Pandas Swim?
Giant pandas can swim and are excellent swimmers. They swim to escape predators and can often be found near freshwater. There is not much information on pandas swimming, but in the video below, you can see that they can swim at about the same as their usual walking pace.
Although Giant Pandas are not found in the wild in North America, I wanted to include them here as many people ask me if they can swim.
Can Koalas Swim?
Koalas aren’t bears but marsupials, but because so many people think they are bears, I have included them here.
Koalas can swim but need a way to get out of the water; otherwise, they will drown. Unfortunately, many koalas pass away in swimming pools and ponds because they cannot get out.
References and Further Reading
Canadian science publishing – Long-distance swimming by polar bears
Nathab – Arctic Adaptations
PMC – Aquatic behavior of polar bears