Natural Histories

photograph of a Sunda Pangolin

Northern River Otter

Lontra canadensis


Northern River Otters are semi-aquatic mammals. The body of a river otter is long and streamlined with a tapered tail and short legs with webbed feet. The head of this animal is wide and rounded with small ears. The dark brown fur of the otter lightens in color on the underside of the belly, chest and face. This fur is very thick and soft to insulate the river otters while in water. A river otter can weigh between 5-14 kg. Male river otters are typically larger than females .


The northern river otter can be found throughout Canada and the United States (except for southern California, New Mexico, Texas, and the Mohave Desert of Nevada and Colorado. They can also be found in the delta areas of the Rio Grande and Colorado River of Mexico. This animal lives in habitats with easy access to unpolluted, freshwater or coastal marine waterways such as; rivers, lakes, marshes, swamps, and estuaries. River otters can endure warm and cold temperatures as well as high elevations. These animals build dens in the burrows of other animals near water. They have also been known to build dens in natural hollows (under a log) or in river banks. These dens usually have underwater entrances and tunnel leading to a nest chamber.

Feeding Behavior and Diet

Northern river otters mostly consume aquatic organisms; including amphibians, fish, turtles, crayfish, crabs, and other invertebrates. Birds, eggs and small terrestrial mammals are occasionally consumed. The high metabolism of this animal requires river otters to consume a lot of food during the day. Northern river otters usually hunt at night but can be viewed at all times of the day. The long whiskers of this species are used for tactile sensation or “touch” while hunting; this is helpful when hunting in murky waters.


Males and females of this species typically breed during late winter- early spring. Males usually breed with more than one female. The gestation period of a river otter is two months but litters can be born later because the female is capable of delaying implantation. Litters of 1-6 young are usually born from November- May in a den near the water. The young are weaned after about 6 months to one year; typically the young are weaned at 3 months old and leave their mother after 6 months. This species does not reach sexual maturity until 2-3 years of age.

Months and Times of Activity

Northern river otters can be found active all year long, living alone or in family groups (females and their young). The peak activity of this animal occurs at night, leaving the den at twilight and hunting all night and into the mid-morning. River otters continue to forage, swim and play throughout the day.

Special Features, Stories, Relationships

•    This is a playful species; river otters have a very high metabolism which provides plenty of energy to play. Individuals or groups play as a way to strengthen social bonds, practice hunting techniques and to scent mark.
•    River otters can close their nostrils underwater while they swim. As excellent swimmers and divers, this species can stay underwater for 8 minutes. River otters are agile on land as well as in water, they can run up to 29 km/hr on land.
•    To read legends featuring this animal go to;
•    Children’s book featuring this animal: River Otter at Autumn Lane by Laura Gates Galvin


D Ellis, E. 2003. "Lontra canadensis" (On-line), Animal Diversity Web. Accessed November 04, 2014 at

"River Otter (Lutra Canadensis Schreber)." Adirondack Ecological Center. New York State University, College of Environmental Science and Forestry (ESF), 1988. Web. 26 Feb. 2013.