River Otter (Lontra canadensis)
by A. Karuna Lohmann
The Narrow River Preservation Association chooses a different organism as its mascot annually to depict on the logo of the Narrow River Turnaround Swim T-Shirt. This year it is a North American River Otter (scientific name Lontra canadensis). Although the River Otter is abundant in Rhode Island, it is rarely seen because it is shy and lives mainly on land. A good indication of its presence, however, are the piles of shells and fish scales it leaves scattered on rocks and banks (Reid 471).
If you have seen a photo of an otter before, an image may come to mind of a cute creature swimming on its back, head above water. This image would be of a Sea Otter (scientific name Enhydra lutris), not a River Otter because the habit of swimming on its back is a key characteristic that distinguishes the Sea Otter from the River Otter (“River Otters | Seattle Aquarium”). Although both species are members of the weasel family Mustelidae, they can be distinguished in numerous ways. Most importantly, unlike the Sea Otter, the River Otter predominantly lives on land. In winter it uses water bodies including iced-over lakes to find food (“River Otters | Seattle Aquarium”) and breathes using air pockets under the ice (“River Otter Wildlife Note”). It also has a playful habit of sliding and galloping across ice. The two otter species also differ in size and coloration. The Sea Otter lives only in the Pacific Ocean (“Scientific Classification”).
Here’s a video of an otter in South Kingstown, RI. Many thanks to Elise Torello for the use of her video.
The River Otter is large, with a body spanning 26-31 inches. As a semi-aquatic animal, it has a thick tapered tail, broad webbed feet, and a streamlined form that makes it well-adapted to both land and water. In contrast, the Sea Otter is three times as large and has a narrower tail. The River Otter’s sleek coat is rich brown with a silvery underbelly and its pale orange eyes have a bright eyeshine (Reid 471). The sensitive whiskers on its muzzle are used to hunt various fish, which are an important part of its diet. The River Otter also preys on shellfish, amphibians, reptiles, insects, birds, and other mammals.
The River Otter is native to North America. It is found in the Eastern United States, Alaska, and large swaths of Canada. In these regions, the River Otter’s primary habitat is land near marine and freshwater bodies of water, such as Narrow River and Narragansett Bay, where it lives in above or below-water dens or abandoned shelters of other animals (“River Otters | Seattle Aquarium”). Breeding occurs in the spring. Females normally have a litter of 2-4 pups that they raise alone (Brown 3).
Although the River Otter population has declined in America in the past due to the pollution of its habitat, protection of the species and water quality monitoring have slowly aided their comeback (Brown 3). Likewise, in Rhode Island, the passing of legislation, the creation of habitats, and the improvement of water quality have helped the River Otter population rise and stabilize (Brown).
Works Cited
Brown, Charles. “Species Spotlight: River Otter.” Wild Rhode Island, 2009, pp. 3–4. Division of Fish and Wildlife, RI Department of Environmental Management, dem.ri.gov/sites/g/files/xkgbur861/files/programs/bnatres/fishwild/pdf/wriwin09.pdf.
Reid, Fiona. A Field Guide to Mammals of North America North of Mexico. Boston, Houghton Mifflin Co, 2006.
“River Otter Wildlife Note.” Pennsylvania Game Commission, 2023 www.pgc.pa.gov/Education/WildlifeNotesIndex/Pages/RiverOtter.aspx.
“River Otters | Seattle Aquarium.” 2023 www.seattleaquarium.org, www.seattleaquarium.org/animals/river-otters.
“Scientific Classification” 2023 https://seaworld.org/animals/all-about/otters/classification/#
