#CreatureFeature: North American River Otter

Posted on Wednesday, Jun 3rd, 2015
North American River Otter

Species: North American River Otter

Trip: Any rafting, hiking or fishing trips in Idaho or Oregon

Habitat: North America Waterways

Likelihood of Encountering: Moderate

Though relatively small, the North American River Otter is still an exciting animal to see in the wild. This playful mammal with it's sleek fur can be seen bobbing in and out of the water amongst the rivers of the Northwest, including the Rogue, Snake, and Salmon Rivers in Oregon and Idaho. 

North American River Otter

While river otters look similar to their sea otter relatives, they are much smaller (about 3-4 feet compared to around 6 feet), and are semi-aquatic (sea otters typically only come on land for short periods to rest or give birth). River otters have short, thick fur, usually grey, brown or black, that helps regulate their temperature in cold water and weather. 

Their webbed feet help them swim quickly, while their length and lean bodies help them easily glide through the water. Their long tails, making up about one-third of their body's length, act as propellers as they swim through the water. Being nimble and alert allows them to make quick movements, helping them catch fish and other food.

Members of the weasel family, river otters can stay underwater for about eight minutes at a time, and close their nostrils and ears to keep out the water during longer submersions. They can dive to depths of about 60 feet!

River otters aren't confined to the water, and in fact spend quite a bit of time on land. They can run as fast as 15 miles per hour on land!

Most active at night, otters are a lively bunch, and can be seen playing games, sliding around in the mud (often a sign of river otters, you may see "slides" down a river's muddy banks), playing in the water, and chasing their tails, among other activities. While playful in nature, these activities also teach young otters important survival skills.

Although they're called "river otters," they can be found in lakes, reservoirs, ponds, wetlands and along marine coasts, and can survive in fresh, brackish or salt water. 

Otters typically hunt at night, and are not too picky when it comes to food. Although fish are a river otter's favorite meal, they also eat frogs, small reptiles, birds' eggs, crabs, other small mammals such as rabbits, and even aquatic plants. River otter's can metabolize their food in about an hour, so they eat pretty regularly! 

You'll find a river otter's den along the banks of the water, in little hallows or burrows. Like a little fort, dens have underwater-accessways so that the otters can easily get in and out through the water. Dens are usually made up of numerous tunnels. Bobcats, coyotes, raptors and other large predators occasionally hunt river otters. 

River otters mate in the late winter or early spring, and typically have one to three pups. Males don't help raise their young. When first born, the otter pups are unable to see. After about two months, they start learning to swim, usually when mom pushes them into the water! Because otters are natural swimmers, and with a little of mom's help, the young learn very quickly.

North American river otter families often live alone, but sometimes in small communities. Families usually consist of an adult female and her pups, or groups of individual males. They talk to each other using whistles and growls, and even with their body language and marking.

In the past, and even in some places today, river otters were hunted for their fur. Due to over-hunting, they were nearly extinct in some places. Today, thanks to wildlife conservation and successful re-introduction efforts, many populations are growing stronger. It is important for us to help take care of their natural habitat and protect water quality to ensure their continued survival in the wild.

River otters are sometimes seen on our Rogue, Snake, and Salmon River trips, among others.

 

Resources:

  • https://www.nwf.org/Wildlife/Wildlife-Library/Mammals/North-American-River-Otter.aspx
  • http://www.defenders.org/north-american-river-otter/basic-facts
  • http://animals.nationalgeographic.com/animals/mammals/american-river-otter/
  • http://wdfw.wa.gov/living/river_otters.html