Lontra canadensis
northern river otter

North American river otters once occurred throughout Canada and the United States, except for areas of southern California, New Mexico, and Texas, and the Mohave desert of Nevada and Colorado. In Mexico they are found in the delta areas of the Rio Grande and Colorado river. These otters are now rare or locally extinct throughout much of the eastern, central, and southern United States.

North American river otters are found anywhere there is a permanent food supply and easy access to water. They can live in freshwater and coastal marine habitats, including rivers, lakes, marshes, swamps, and estuaries. River otters can tolerate a variety of environments, including cold and warmer latitudes and high elevations. North American river otters seem to be sensitive to pollution and disappear from areas with polluted waters.

North American river otters build dens in the burrows of other mammals, in natural hollows, such as under a log, or in river banks. Dens have underwater entrances and a tunnel leading to a nest chamber that is lined with leaves, grass, moss, bark, and hair.

North American river otters are semi-aquatic mammals, with long, streamlined bodies, thick tapered tails, and short legs. They have wide, rounded heads, small ears, and nostrils that can be closed underwater. The vibrissae are long and thick, reflecting their importance in sensory perception. The fur is dark brown to almost black above and a lighter color ventrally. The throat and cheeks are usually a golden brown. The fur is dense and soft, effectively insulating these animals in water. The feet have claws and are completely webbed. Body length ranges from 889 to 1300 mm and tail length from 300 to 507 mm. Weight ranges from 5 to 14 kg. Males average larger than females in all measurements.

North American river otters can live up to 21 years in captivity. They normally live about 8 to 9 years in the wild.

Lontra canadensis individuals are solitary, except for females with their young. They are known as playful animals, exhibiting behaviors such as mud/snow sliding, burrowing through the snow, and waterplay. Many "play" activities actually serve a purpose. Some are used to strengthen social bonds, to practice hunting techniques, and to scent mark. North American river otters get their boundless energy from their very high metabolism, which also requires them to eat a great deal during the day.

They are excellent swimmers and divers, able to stay underwater for up to 8 minutes. They are also fast on land, capable of running at up to 29 km/hr. These otters normally hunt at night, but can be seen at all times of day.

Home Range

River otters have large home ranges, between 2-78km of waterway, and are constantly on the move within this range. Home range sizes vary considerably and seem to depend on the richness of food resources and habitat quality. Despite these large ranges, river otters are only slightly territorial and generally practice mutual avoidance.

North American river otters communicate in a variety of ways. They vocalize with whistles, growls, chuckles, and screams. They also scent mark using paired scent glands near the base of their tails or by urinating/defecating on vegetation within their home range. These glands produce a very strong, musky odor. They also use touch and communicate through posture and other body signals.

North American river otters perceive their environment through vision, touch, smell, and hearing. Their large and abundant whiskers are very sensitive and are important in tactile sensation. These whiskers are used extensively in hunting, as smell, vision, and hearing are diminished in the water.

North American river otters eat mainly aquatic organisms such as amphibians, fish, turtles, crayfish, crabs, and other invertebrates. Birds, their eggs, and small terrestrial mammals are also eaten on occasion. They sometimes eat aquatic plants.

Prey is captured with the mouth, and mainly slow, non-game fish species are taken, e.g., suckers. The otter's long whiskers are used to detect organisms in the substrate and the dark water. Prey is eaten immediately after capture, usually in the water, although larger prey is eaten on land.

North American river otters are sometimes taken by bobcats, coyotes, birds of prey, alligators, and other large predators. They mainly escape predation through their agility in the water and on land, their vigilance, and their ability to fiercely defend themselves and their young.

North American river otters are important predators of fish and aquatic invertebrates.

North American river otters generally do not have adverse affects on humans.

North American river otters are important parts of healthy, aquatic ecosystems.

North American river otters have been hunted for many years for their attractive and durable fur. In the 1983-84 hunting season, 33,135 otters were taken with an average selling price of $18.71 per pelt. Otters are stll an important source of income for many people in Canada and the western United States. River otters also eat "trash fish" that compete with more economically desirable game fish.

Lontra canadensis is listed in Appendix II of CITES. They have been virtually eliminated through many parts of their range, especially around heavily populated areas in the midwestern and eastern United States.