Polar bears are classed as marine mammals and are excellent swimmers, but you may be unaware if other species can also 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 marine mammal.
Can Black Bears Swim?
Black bears live terrestrially and have a primarily herbivorous diet. Black bears only swim only when needed, such as during the popular salmon spawning season. Black bears enter the water while fishing for salmon which are on their way to spawning upstream, but the best fishing spots are in the shallow waters where no swimming is required.
The cubs of black bears cannot swim until they reach about 30 pounds. Black bears with cubs usually don’t go to deep fishing spots, as their cubs may be at risk of danger from larger, more dominant male bears. This means that the cubs may not need to swim until later in life.
Black bears are adequate swimmers, but they only swim short distances of several kilometers to cross a lake or from one island to another.
Can Brown Bears Swim?
Brown bears can swim and propel themselves forward with a 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 due to their size, so they cannot swim long distances. Cubs are usually kept from popular salmon spawning areas as larger male 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 the islands have different 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 excellent swimmers. They are classed as marine mammals partly due to the amount of time they spend in the water. Polar bears have several adaptations to travel long distances without stopping.
The paws of a polar bear are webbed, which allows them to pull themselves through the water quickly and without spending much energy.
One female swam for nine days with a small break in the middle, traveling 687 km (426 miles). It is thought that longer distances will need to be traversed in the future due to climate change and the lack of sea ice.
Polar bears have a thick layer of fat called blubber, which helps keep them insulated when swimming long distances.
How Do Bears Swim?
Bears have a similar body shape and physiology to dogs and swim using a doggy paddle. The doggy paddle stroke uses the front limbs in a paddling motion, while the back legs are used very little.
Polar bears have large paws which are partially webbed to aid in propulsion through the water and stability while traversing the ice sheets.
The doggy padle is inefficient and energy can be depleted quickly, meaning that brown and black bears cannot swim long distances.
Black and brown bears are less efficient swimmers than the polar bear. Their habitats are 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 small 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?
- Foraging: Bears often swim to search for food. They are strong swimmers and can cover long distances in water. They may swim in rivers or lakes to catch fish, especially during salmon runs when fish are abundant.
- Cooling Off: Like many animals, bears swim to cool off in hot weather. Water helps regulate their body temperature, and a refreshing swim can provide relief from heat.
- Crossing Water Barriers: Bears sometimes need to cross bodies of water to access different habitats, find food, or escape predators. Swimming allows them to navigate these barriers.
- Escaping Predators: If a bear feels threatened on land, it may take to the water to escape from potential threats. Bears are generally excellent swimmers and can outpace many of their predators in the water.
- Play and Social Interaction: Young bears, in particular, enjoy playing in the water. It’s a way for them to practice swimming skills and engage in social interactions with other bears.
- Mating and Reproduction: During the mating season, male and female bears may swim to find each other. This can be a part of their natural behavior during the breeding season.
- Habitat Exploration: Bears are curious animals, and swimming can be a way for them to explore their environment. They might investigate new areas or territories by swimming to them.
- Personal Preference: Like humans, individual bears may have their preferences. Some bears simply enjoy being in the water and may swim for leisure.
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, as recorded in the Guinness World Records. Polar bears generally swim for up to 10 hours a day before resting.
Brown bears have been seen swimming across the canals between the ABC islands in Southeast Antarctica, some as far as 1.6km apart.
- Polar Bears: Polar bears are powerful swimmers and are known to swim for extremely long distances in the Arctic Ocean. They can swim for many miles, often covering 48-97 kilometers (30-60 miles) at a stretch, and have been recorded swimming over 160 kilometers (100 miles) without rest. They rely on swimming to hunt for seals on ice floes.
- Grizzly Bears: Grizzly bears are also strong swimmers, although they tend to swim shorter distances compared to polar bears. They may swim across rivers and lakes, and some have been observed swimming several miles at a time.
- Black Bears: Black bears are competent swimmers and can easily cross rivers and swim across lakes. They are known to swim for several miles when necessary.
- Brown Bears: Brown bears, including coastal brown bears (also known as Kodiak bears), are proficient swimmers. They often swim between islands and along coastlines in search of food. While there aren’t many recorded data points, some individuals have been observed swimming for several miles.
How Fast Can Bears Swim?
- Polar Bears: Polar bears are considered excellent swimmers and can maintain an average swimming speed of around 6 miles per hour (9.7 kilometers per hour). They are known to swim for long distances in the Arctic Ocean in search of seals.
- Grizzly Bears: Grizzly bears are also competent swimmers and can swim at an average speed of about 3-5 miles per hour (4.8-8 kilometers per hour). They often swim across rivers and lakes.
- Black Bears: Black bears are capable swimmers, and their swimming speed is estimated to be around 4-5 miles per hour (6.4-8 kilometers per hour). They swim to cross bodies of water and access new habitats.
- Brown Bears (Including Kodiak Bears): Brown bears are good swimmers and can swim at a pace similar to that of grizzly bears, around 3-5 miles per hour (4.8-8 kilometers per hour). Coastal brown bears, such as Kodiak bears, are known to swim between islands and along coastlines.
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 swim at about 15 weeks of age. Because swimming requires lots of energy, swimming long distances is not done until much later.
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 has finished.
Black and brown bear cubs cannot swim until they are around 30 lbs (13.6 kg), whereas polar bear cubs are usually about 40 lbs. (18 kg)
Can Giant Pandas Swim?
Giant pandas are not known for their swimming abilities, and they typically avoid the water. Unlike some other bear species, such as polar bears, which are strong swimmers and spend a significant amount of time in the water, giant pandas are more terrestrial in their habits.
Giant pandas can 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 have several adaptations that make them poorly suited for swimming. They have relatively short limbs with sharp claws designed for gripping tree branches rather than propelling through water. Additionally, their bodies are not streamlined like those of animals built for swimming, such as seals or dolphins.
While koalas may be able to stay afloat for a short time if they find themselves in the water, they generally avoid swimming whenever they can. In the wild, they primarily inhabit eucalyptus trees and rely on their specialized diet of eucalyptus leaves for sustenance. If they need to move between trees, they prefer to walk or climb rather than swim.
References And Further Reading
Canadian science publishing – Long-distance swimming by polar bears
Nathab – Arctic Adaptations
PMC – Aquatic behavior of polar bears
Bears of the World by Lance Craighead and Donald Craighead
This comprehensive book provides insights into the lives of bears, including their behaviors and adaptations.
The World of the Polar Bear by Norbert Rosing
While focused on polar bears, this book contains information about polar bear swimming behavior, given their strong association with water.
Bears: A Brief History by Bernd Brunner
This book explores the cultural and natural history of bears, and it also contains information about their swimming behavior.
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.