北極熊
The polar bear is an excellent swimmer and often will swim for days. One bear swam continuously for 9 days in the frigid Bering Sea for to reach ice far from land. She then travelled another . During the swim, the bear lost 22% of her body mass and her yearling cub died. With its body fat providing buoyancy, the bear swims in a dog paddle fashion using its large forepaws for propulsion. Polar bears can swim at . When walking, the polar bear tends to have a lumbering gait and maintains an average speed of around . When sprinting, they can reach up to .