The polar bear, also known as the polar bear, is a species of predator from the bear family (Ursidae). It lives on the coasts and on the ice in the northern polar regions and is closely related to the brown bear. Along with Kamchatka bears and Kodiak bears, polar bears are considered the largest land-dwelling predators on earth. As they spend a large part of their lives on the sea ice and are dependent on marine ecosystems, they are also classified as marine mammals.