River Otter

Lontra canadensis

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  • River Otter | The National Geographical Society c1916 Photo: Keenan Adams, USFWS
  • River Otter | The National Geographical Society c1916 Photo: Keenan Adams, USFWS
  • River Otter | The National Geographical Society c1916 Photo: Keenan Adams, USFWS
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Basic Information






are generally between 35 and 51.25 inches in length.


up to 12 years


River Otter (Lontra canadensis) facts, habitat, diet, range, otter pictures and more to help you learn to identify the marine mammal.




River Otters reach sexual maturity by age three. Males and females don't associated with one another except during breeding season. Males will mate with more than female if given the opportunity.


Nationwide except extreme arid environments

Number of Offspring

1-6 Pups

What does the River Otter look like?

North American River Otters are stocky carnivores with short legs, long bodies and long tapered tails. Males are slightly larger than females, but both sexes look alike. They have short ears and small nostrils that can both be closed when underwater. Their short extremely dense fur is a dark brown to nearly black, with a slightly lighter coloration on the throat and cheeks. Their feet have sharp claws that are webbed.

River Otter Habitat


River Otter Facts

River Otters are a semi-aquatic member of the weasel family. But unlike, other weasels, fishers, mink and martens they have evolved for life in the water. They have oily waterproof fur, webbed feet, small ears and nostrils that can be completely shut to keep water out. They are amazing swimmers and can stay under water for up to 8 minutes at a time. However, they are also quite fast on land, capable of running 18 miles per hour. They are mostly carnivorous, feeding on fish, birds and small mammals, but will occasionally eat some vegetation. They have specialized vision that allows them to see potential prey in darky murky water. They use their whiskers to detect vibrations and thus how far away prey is from them. If that's not enough, River Otters also have an incredible sense of smell. All of this helps them keep up with their astonishingly fast metabolisms. When a River Otters enjoys a snack, the majority of it has passed through their digestive track within an hour. They are also extremely playful animals. Their spirited fights often include somersaulting, wrestling and flopping around. That said this serves several very important roles. First off, it strengthens social bonds, teaches them hunting techniques and to scent mark. It also teaches young otters how to defend themselves. Which like other members of the weasel family; River Otters are very capable fighters when they need to be, especially when protecting their young. That's not to say they don't fall victim to predators. Wolves, bears, birds of prey, coyotes and bobcats commonly kill River Otters when they are on land. When they are in the water, they are likely to escape, as they are much better swimmers than all of the above. River Otters used to be widespread across the country, however fur trade and other factors such as pollution has extrapolated them from certain parts of their historic range.

See also