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!