The North American river otter (Lontra canadensis), also known as the northern river otter or the common otter, is a semiaquatic mammal endemic to the North American continent, found in and along its waterways and coasts.
The North American river otter (Lontra canadensis) became one of the major animals hunted and trapped for fur in North America after European contact.
Description: Stocky animal of 5 to 14 kilograms (11 to 31 lb), with short legs, a muscular neck no smaller than the head, and an elongated body that is broadest at the hips. An average adult male weighs about 11.3 kilograms (25 lb) against the female's average of 8.3 kilograms (18 lb). Its body length ranges from 66 to 107 centimetres (26 to 42 in). About one-third of the animal's total length consists of a long, tapered tail. Tail lengths range from 30 to 50 centimetres (12 to 20 in). Large male North American river otters can exceed a weight of 15 kilograms (33 lb). It differs from the European otter by its longer neck, narrower visage, the smaller space between the ears and its shorter tail.
Habitat: Although commonly called a " river otter" , the North American river otter is found in a wide variety of aquatic habitats, both freshwater and coastal marine, including lakes, rivers, inland wetlands, coastal shorelines and marshes, and estuaries. It can tolerate a great range of temperature and elevations. A river otter's main requirements are a steady food supply and easy access to a body of water. However, it is sensitive to pollution, and will disappear from tainted areas Like other otters, the North American river otter lives in a holt, or den, constructed in the burrows of other animals, or in natural hollows, such as under a log or in river banks. An entrance, which may be under water or above ground, leads to a nest chamber lined with leaves, grass, moss, bark, and hair. Den sites include burrows dug by woodchucks (Marmota monax), red foxes (Vulpes vulpes), nutria (Myocastor coypus), or beavers, or beaver and muskrat (Ondatra zibethicus) lodges. River otters also may use hollow trees or logs, undercut banks, rock formations, backwater sloughs, and flood debris. The use of den and resting sites is chiefly opportunistic, although locations that provide protection and seclusion are preferred.
Food: Like most predators, Otters prey upon the most readily accessible species. Fish is a favored food among the otters, but they also consume various amphibians, turtles, and crayfish. Instances of river otters eating small mammals and occasionally birds have been reported, as well.
Activities: Otters are very active, chasing prey in the water or searching the beds of rivers, lakes or the seas. Most species live beside water, but river otters usually enter it only to hunt or travel, otherwise spending much of their time on land to avoid their fur becoming waterlogged. Sea otters are highly aquatic and live in the ocean for most of their lives. Otters are playful animals and appear to engage in various behaviors for sheer enjoyment. Different species vary in their social structure, with some being largely solitary, while others live in groups – in a few species these groups may be fairly large.