River otters (Photo by John E. Marriott)

River otter

This playful mammal is making a splash across Canada.

Size and appearance

River otters can measure up to 1.4 metres in length from nose to tail, and weigh up to almost nine kilograms. They have brown, water-repellent fur, webbed feet and long tails. Their underbody is usually lighter in colour. Their tiny ears close under water, and their thick fur helps keep them warm in cold water. Long whiskers help them find fish, clams, insects and other aquatic animals.

Range and habitat

River otters can be found throughout North America. In Canada, they can be found in every province and territory except Prince Edward Island, where they appear to be extirpated.

They are able to live in a variety of different habitats, including rivers, lakes and large creeks. River otters thrive outside of water too, and can sometimes be seen playing in snow or sliding down muddy hills.

Their burrows are typically found near water and are often built to be accessible both from on land and in the water.

Just keep swimming

River otters breed between late winter and early spring. Although they are able to reproduce annually, it is more likely for this species to give birth every two years. Female otters give birth to between one and six pups. The pups are born blind and spend the first month of their lives in their dens with the female. After two months, the female otter teaches the full-sighted pups how to swim.

This species does not hibernate and remains active under frozen water by breathing through breaks in the ice. River otters are able to hold their breath underwater for up to eight minutes.

Hand in paw with otters

River otter populations declined significantly throughout the late 1800s due to over-harvesting and water pollution. However, through conservation management and reintroduction efforts, populations have recuperated and are now considered stable.

River otters need healthy aquatic habits to survive. The Nature Conservancy of Canada (NCC) continues to protect habitat across Canada where river otters live. One example is NCC’s Cherry Meadows property, near Kimberly, British Columbia. Located in the Rocky Mountain Trench, this area features extensive wetlands that are perfect for river otters.