About River Otters

River Otter

Lutra canadensis

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Lontra
Species: L. canadensis

Fast Facts

Lifespan: 8-10 years in the wild (up to 20 years in captivity)
Size: 35-50 inches long, weight of males 15-20 pounds, females about one-third less
Offspring: 2-3 kits
Status: Common in parts of southern Canada and populations increasing in the eastern United States

What do river otters look like and what animals are their relatives?  River otters are dark brown, fading to tan on the underside and on the muzzle and throat. Their coats consist of two kinds of fur – a dense, short, oily underfur and long, shiny guardhairs.  Streamlined for swimming, with cylindrical bodies and long, tapering, round tails, otters are never far from water. Eyes, plus a flattened dark nose and small rounded ears are towards the top of the skull. Webbed feet greatly enhance an otter’s swimming abilities.  Otters are members of the family Mustelidae and thus are related to mink, fisher, weasels and martens.

What kind of habitat to otters prefer?  Masters of the waterways, otters are found in the moving water of rivers and streams as well as in marshes, ponds, lakes, and saltwater.  The home range of an otter is typically 3-10 square miles, but may be as large as 60 square miles. A male otter has a larger territory that usually overlaps that of several females. Dens are used in raising the young and may be an old beaver lodge or bank den, a spot under the roots of fallen trees or in hollow logs close to water.

What do otters eat?  
While fish make up the major portion of their diet, otters also prey on crayfish, frogs, small mammals, aquatic insects, turtles, water snakes and even eat some plant material like blueberries.

Do otters have some special adaptations?  Otters have special adaptations for living in water that give them to ability to dive to a depth of 60 feet and stay underwater of up to three or four minutes. As they dive below the surface, otters automatically slow their heart rate and concentrate blood flow to the brain and vital organs, thus conserving oxygen.  Valves in their ears and nostrils close to exclude water and a clear nictitating membrane (third eyelid) covers and protects the eyes while allowing for good vision. Whiskers two to four inches long are sensitive to underwater vibrations from prey.

Fun Facts!

• Otters can swim at six to seven miles per hour both above and below water.
• Otter slides? Yes, otters will slide down muddy, grassy or snowy slopes and these slides may be up to 25 feet long, usually ending in water.
• Otters are very playful, wrestling and chasing each other and rolling in the water.
• An otter’s fur is waterproof because the oily underfur is so dense and is structured in an interlocking pattern, keeping water away from the otter’s skin.  
• Clean water is essential to otters so seeing one indicates a healthy waterway.

Fast Facts about North American River Otters

By Alexa Cushman, Program Intern

In the short time that I have been interning at Squam Lakes Natural Science Center I already have a favorite exhibit animal, the adorable and playful North American river otters. I know I am not the only visitor that enjoys watching the otters gracefully swim through the water, and play with each other. These enjoyable mammals can be found across North America, always near a body of water. Otters have amazing adaptations that help them survive in the wild and excel as predators both in water and on land. Their body is streamlined, with a long rounded tail, and they have webbed feet to help propel them through the water. They are able to close both their ears and nose by using specialized muscles so they can stay underwater for up to eight minutes. River otters are able swim up to 6 or 7 miles an hour both on the surface and under the water! They are even faster on land and they have been known to run up to 18 miles an hour to escape predators.

If you stay at the exhibit long enough, or if you have been to River Otter Feeding, you have probably seen the otters playing. North American river otters are very playful in the water and on land. Often wild otters can also be seen playing in the water, and sliding through the mud. Sometimes their slides can even be 25 feet long. Other than just for fun, these activities and behaviors are actually used to strengthen social bonds, or practice hunting techniques.

These intelligent mammals use many different forms of communication. They vocalize through various growls, whistles, chuckles, and screams, and can have up to a dozen different vocalizations. River otters are a part of the Mustelidae family which includes weasels, marten, fisher, and mink. Most animals in this family are able to communicate in a very different way than most other animals; through scent markings. Otters have scent glands near the base of their tail that produce a musky odor. They use this form of communication mainly to mark their territory. They also communicate through posture and other body signals just like us.

Even though river otters can be found throughout the United States, they are not commonly seen animals. They are mostly nocturnal and tend to den in sites that have a lot of bush cover for protection. In the twentieth century otters were often hunted and trapped for their rich, waterproof furs. Hunting and increasing water pollution caused otters to be extirpated in many places. Luckily for us, trapping and hunting regulations were developed and there have been many reintroduction efforts to help river otter populations recover. In many areas the river otter is back and doing well, but otters are easily affected by pollution and unclean water so they are not commonly seen around densely populated areas.

These amazing feats and adaptations have allowed the North American river otter to excel as a predator across the United States!

River Otter Feeding

Every Monday, Wednesday, and Friday at 11:30 a.m. from May through October we hold River Otter Feeding. Our expert volunteers will tell you all about otter biology and ecology, while also serving up a tasty treat or two. They'll talk about the history of the two river otters on exhibit at the Science Center while you watch them play and enjoy an early lunch.

River Otter Feeding is included in your regular trail admission. Learn more about otters on our website: http://www.nhnature.org/visit/animal_info_sheets/river_otter.php.

River Otters Playing in the Snow