North American River Otter
Found: United States and Canada
Size: 3 to 4 feet
Weight: 11 to 30 pounds
Diet: fish, rodents, frogs, crabs, birds
Life Span: 8 to 9 years
Built for swimming, river otters have dense fur with a waterproof undercoat, a layer of fat that insulates the body and a torpedo-shape, which is very useful for swimming. They also have a clear eyelid that acts like swim goggles, can stay underwater for up to eight minutes and can close their
ears and nostrils to keep water out. Ironically, babies have to be taught to swim. When the young are only about two months old, mom gives them a swimming lesson—she simply pushes them into the water and then stays close pushing them under the water and then up to breath. When the lesson is over she grabs it by the neck and pulls it out of the water. On land, they can get around and run quite well, if not as effectively as they swim. They find slippery rocks and slide into the water on their bellies, or they leap in with somersaults and belly flops. They are often seen enjoying wrestling matches with each other.