Family: Muridae, Mice and Rats view all from this family

Description A medium-sized, brown, aquatic rodent. Back is dark brown, underside is slightly paler. Black tail is vertically flattened. Long, coarse, glossy guard hairs cover the short, dense, silky underfur. Partially webbed hind feet are larger than the forefeet. Fringes of stiff hairs along the sides of the toes further enhance swimming ability.

Dimensions 41-62cm, 18-30cm, 700-1800g

Similar Species Larger-bodied in the north of their range. Clearly larger than the Round-tailed Muskrat and smaller than the Coypu or Beaver.

Habitat Swamps, marshes & bogs, Beaches, shorelines & estuaries, Lakes, ponds, rivers & streams

Range Plains, Great Lakes, New England, Mid-Atlantic, Rocky Mountains, Southeast, Southwest, Texas, California, Northwest, Eastern Canada, Western Canada, Alaska

Discussion Uses cut vegetation to build rounded houses about 2m in diameter and 1m high; also dens in holes dug into the shore. Crepuscular and nocturnal feeder on a variety of aquatic plants. Common in brackish and freshwater lakes, rivers, and swamps.