North American River Otter

The North American River Otter (Lontra canadensis), also known as the Northern River Otter or the Common Otter, is a semi-aquatic mammal endemic to the North American continent, found in and along its waterways and coasts. An adult river otter can weigh between 5 and 14 kg (11 and 30 lb). The river otter is protected and insulated by a thick, water-repellent coat of fur.
The river otter, a member of the weasel family, is equally versatile in the water and on land. The otter establishes a burrow close to the water's edge in river, lake, swamp, coastal shoreline, tidal flat, or estuary ecosystems. Their dens have many tunnel openings—one of which generally allows the otter to enter and exit the body of water. Female otters give birth in these underground burrows, producing litters of one to six young.
North American river otters, like most predators, prey upon the species that are the most readily accessible. Fishes are a favored food among the otters, but they also consume various amphibians, turtles, and crayfish. There have been instances of river otters eating small mammals as well.
The range of the North American river otter has been significantly reduced by habitat loss, beginning with the European colonization of North America. However, in some regions their population is controlled to allow the trapping and harvesting of otters for their pelts. River otters are very susceptible to environmental pollution, which is a likely factor in the continued decline of their numbers. A number of reintroduction projects have been initiated to help stabilize the reduction in the overall river otter population.