Species Often Confused with River Otters

Correctly identifying otter presence can be challenging, especially if you’ve only had a quick glance of the animal or sign (tracks, scat, or damage). Species that are often confused with otter are beavers, raccoons, mink, and muskrats. Knowing a little about each of these other species can help you easily distinguish them from otters. 

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Beaver
Raccoon
Mink 
Muskrat

Beaver

Beavers are confused with otters because beavers and otters look alike while swimming, and both leave slides along the banks. When swimming, beavers have their backs and head out of the water, while river otters have just their head and neck above the water’s surface. Slides can be almost indistinguishable, but chewed trees and sticks are a telltale sign of a beaver, while fish heads are indicative of otters. Beaver scat is easily distinguished from otter scat by its lack of fish scales and crayfish remains, cylindrical shape, and often sawdust like texture. In addition, both beaver and otter tails are flattened; however, beaver tails are flattened like a wide, rounded paddle, while otter tails are much narrower, taper to a point, and are covered with fur.

Raccoon

As mentioned previously, raccoons and otters have scat that resembles one another. Raccoon scat, however, will consist of berries and other vegetation while otter scat is primarily composed of fish scales, especially in the winter months. Raccoon tracks can be distinguished by their shape (raccoon tracks often resemble pointed hands or a five-pointed flipper), and otters, unlike raccoons, have webbing between their toes which can be present in an otter track. 

Mink

Because mink and otters are in the same family (Mustelidae), they highly resemble each other. To tell these two species apart, size is the most important factor. Otters are large, almost 4 feet long, while mink are significantly smaller, measuring less than 2 feet in length. Mink tracks will also resemble those of otters in appearance, however they are much smaller (up to 2in x 2in). Additionally, the tails of mink are short and slightly bushy; whereas, otter tails are long, sleek, and tapered.

Muskrat

Muskrats could be confused with otters as they swim; although, like with mink, size is the key factor in determining the different. Muskrats are medium sized rodents that measure 1-2 feet long, while river otters are 2-4 times longer than a muskrat. Additionally, the tails of muskrats are small, slender, and can appear scaled from a distance, while otter tails are longer, thicker, and visibly furred.