photo by Dezidor
Latin Name: Lontra canadensis
Species: Mammal
Conservation Status: S4-5 - Secure
The river otter has dense fur that is dark brown on the back side and lighter around the throat and belly. Their bodies are incredibly streamlined with a long and muscular tail as they spend a lot of time swimming in the water. They can close up their nostrils, ears, and nictitating membranes while diving. A nictitating membrane is a third eyelid that works similarly to goggles, protecting the eyes of the animal while underwater. Their body ranges from 2.5-5 feet long.
Range & Habitat (map)
They live in riverine and estuary ecosystems throughout most of Canada and a large portion of the U.S. In Canada, they avoid the Arctic. In the U.S., they occur throughout the entire eastern portion of the country, the northwest, and Alaska.
Diet
River otters have a high metabolism which gives them a lot of energy, but they must eat a lot to maintain this lifestyle. They are strictly carnivorous and their diet is primarily composed of other aquatic or marine prey items such as slow-moving fish, crabs, shellfish, crayfish, frogs, and occasionally even birds, turtles, and small mammals.
Life History
River otters can have a large home range, typically from 3-15 square miles, and often interact in groups, seeming playful in nature. The mating season occurs in late winter and early spring. Gestation time for otters is only 2 months but may seem much longer as females can delay fertilization after mating, typically giving birth to 2-3 pups starting in November. Pups are weaned after only 3 months and may start finding their own homes at 6 months.
Significance
Like all predators, the river otter is crucial to the regulation of prey species and the rest of the food web in the fresh and saltwater ecosystems that they inhabit. Besides their ecological impact, they are also important for us as they are charismatic megafauna. They attract tourism, promote outdoor recreation, and the protection of aquatic and marine habitats such as the Port Royal Sound.
Threats & How You Can Help
Historically, the fur trade was the biggest threat that led to regional extirpations of river otters in some areas such as the Midwest. However, due to more recent protections and reintroduction efforts, populations are recovering in the U.S. The fur trade still has some impacts specifically in Canada, where the fur industry is still an important income for many. The new major threats they face are pollution and habitat loss.