Home » Plants & Animals » Mustelidae » River Otters

River Otters

© Josie Shadwell

Some of the North American relatives of this playful little animal include the mink, fisher, ermine, badger, wolverine, and marten.

The average North American River otter or lutra canadensis measures around three feet from nose to tail. They, like their relatives, carry 'musk' in two glands under their tail. This musk is used to mark their territory, at mating time, and sometimes sprayed when the otter is alarmed.

The river otter, sometimes referred to as a freshwater otter, is an excellent swimmer who will glide on his stomach, or flip on his side or back and float. These members of the weasel family have four webbed feet. They are also excellent fishermen. This playful creature uses water to find food, escape from enemies, get to its den, or just play. When in a hurry underwater, this amazing mammal tucks its front legs in close to his chest, back feet will be close to it’s tail, and ripples his body up and down. Being well suited for swimming and diving its sleek streamlined shape helps it cut through the water quickly and its webbed back feet help with paddle power. To turn quickly it uses its long thin tail as a rudder to change direction quickly.

The waterproof coat of the river otter consists of long, stiff guard hairs that shed the water. The short hairs near its body help keep in body heat. It has thick, glossy brown fur, which is commercially valuable but its numbers have been reduced considerably in many regions as a result of excessive trapping and habitat alteration.

The nose has built in nose plugs or folds of skin that cover the otter's nostrils when it dives. It has the same feature for its ears. The head is flattened, the legs are short, and the hind feet are webbed. An agile swimmer, it fishes in streams and lakes, along the banks of which it makes its burrow. It also eats frogs, crayfish, and other water animals feeding mostly at dusk or dawn.

On land, its short stubby legs are powerful and it can move quickly. However, they usually poke along the riverbanks near its home searching for food. The den of the river otter usually has at least two entrances, a bedroom, and sometimes a toilet.

Being active all year long, the otter will swim under the ice for food. Because of his short legs, the otter more often than not tunnels through the snow instead of running on top or he also uses a series of jumps and a slide motion, which resembles tobogganing.