Polar bears are impressive animals that have mastered living in the Arctic. Despite being large land mammals, they are exceptionally skilled at navigating water. Classified as marine mammals, they spend significant time in and around the water, relying on the Arctic Ocean for survival.
Physical Adaptations for Swimming
Polar bears possess unique physical characteristics that allow them to be proficient swimmers in their icy habitat. Their large front paws, which can measure up to 12 inches across, function like paddles for propulsion. These paws are also slightly webbed, aiding their movement. Their hind legs, held flat, serve as rudders to help them steer and control direction while swimming.
A thick layer of blubber, which can be up to 11 cm (4.3 inches) thick, provides insulation and buoyancy. This fat layer helps keep them warm in frigid waters and makes swimming easier by aiding floatation. Their fur, consisting of a dense undercoat and long, hollow guard hairs, offers additional insulation and contributes to buoyancy. This specialized fur repels water and minimizes heat loss once they emerge from the water.
Swimming Behavior and Capabilities
Polar bears exhibit a distinct swimming technique, primarily using their large forepaws to propel themselves in a dog-paddle style. Their hind legs remain extended and flat, acting as a rudder to guide their movement. Polar bears are capable of reaching swimming speeds of up to 10 kilometers per hour (6.2 mph).
They are known for their impressive endurance, swimming for several hours at a time and covering long distances. One notable instance recorded a female polar bear swimming continuously for nine days, covering approximately 687 kilometers (426 miles) in the Beaufort Sea. While swimming, their nostrils close to prevent water entry, and their eyes remain open, allowing them to see underwater. They can also make shallow dives, typically to depths of 3 to 4.5 meters (9.8 to 14.8 feet), and can remain submerged for over a minute, with some observations reporting dives lasting more than three minutes.
Polar bears swim for various reasons, including traveling between ice floes, reaching new islands, or escaping potential threats. They also use swimming as a way to cool down, as their thick insulation can lead to overheating, especially during warmer periods or after physical activity.
The Role of Swimming
Swimming is deeply integrated into the polar bear’s survival strategies and their life in the Arctic. It is important for their hunting, particularly when seals surface for air in open water or near breathing holes in the ice. While seals are generally faster in open water, polar bears employ aquatic stalking techniques, sometimes submerging to approach prey stealthily from below.
The ability to swim is also important for their migration patterns and for navigating their habitat, especially as the sea ice melts seasonally. They rely on swimming to traverse open water sections and move between remaining ice platforms. As the Arctic undergoes environmental changes, the capacity for long-distance swimming becomes even more significant for polar bears, impacting their ability to access hunting grounds and suitable habitats.