As members of the weasel family, California sea otters can walk, but they prefer to spend their lives in the water, sleeping, frolicking and continually stuffing their faces.
Sea otters eat a quarter of their body weight every day, diving up to 350 feet to seek out abalone, urchins, crabs and clams, which they crack open with sharp stones. When it’s time to rest, they wrap themselves in kelp to keep from floating away, before pulling their paws up under their chins to sleep in a posture that is undeniably cute.
Unlike other marine mammals, they have no blubber. Instead, every inch of the sea otter’s pelt has over 850,000 hairs that trap air bubbles and maintain the otter’s body heat. Unless their fur is matted (for instance in an oil spill), water never actually touches the otter’s skin. They spend a quarter of their time grooming, to keep their protective furs in good shape.
In the late 1700s humans came to appreciate their warm coats as well, and by 1820 they were nearly extinct. During the 20th century conservation efforts helped the otter population rebound, but they are still listed as an endangered species.