North American River Otter

River Otter with Fish

Courtesy Eagle Wing Whale Watching Tours


If you think you see a sea otter foraging in the intertidal areas, look again. It's most likely a river otter, which is found in marine as well as freshwater habitats.

These charming semi-aquatic mammals have long, streamlined bodies, thick, muscular tails, weigh 10 to 30 pounds and measure up to 4 feet long (including their tail). Their thick coats are dark brown above, and lighter, with a silvery sheen, below.

Unlike sea otters, they never float on their back, and forage on land and in marine subtidal and intertidal zones in the inland waters. They eat fish, sea stars, crabs, mussels, amphibians, bird eggs, and occasionally Glaucous-winged gull and other chicks. Look for foot-wide slides made out of grass, sand, or dirt near the water's edge. These are feeding areas.

River otters are graceful swimmers, and propel themselves through the water with short, powerful legs and webs between their toes. They're social, gentle, and playful, and have been known to tuck their front feet and slide down an icy hill, then run and slide again. They can also move about on land, where they walk or run, and can travel for long distances.

They are quite vocal, and communicate with a variety of chirps, screams, growls, and whines.

These critters are cute, but islanders have to ensure that crawl spaces are secure, as otters will establish nests if they have the opportunity.

Fast Facts_otter

Last updated: March 1, 2015

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