Before white settlers and trappers reached North American, river otters inhabited most of the Continent; only the High Arctic and Southwest deserts were devoid of these sociable mustelids. Prized for their dense and durable fur, they were extirpated from much of their native range by the 1930s, all but disappearing from the lower 48 States.
Reintroduction programs, many of which began in the 1980s and transplanted individuals from Alaska and Canada, have returned North American river otters to stream, lake and wetland habitats across the U.S.; indeed, some areas have liberalized trapping regulations in light of that success. Though widespread, these playful and agile creatures are primarily nocturnal and are rarely encountered by the casual hiker or naturalist. Never far from water, otters den in hollow logs or use the abandoned burrows of beaver, muskrats, nutria and woodchucks. Their diet includes fish, crayfish, turtles, amphibians, mollusks, aquatic birds and, occasionally, young beaver or muskrats.
Mating occurs from December to March but, due to delayed implantation, the kits (usually 2-4) are not born until late February to April of the following year; the young will be weaned in three months and leave the family group within nine months. Potential victims of coyotes, wolves, bears, bobcats, mountain lions and alligators, river otters have a natural life span of 8-9 years.
