River otters are water-adapted mammals, with long, streamlined bodies, short legs, webbed toes, and long, tapered tails. Their short, thick fur is a rich brown above, and lighter, with a silvery sheen, below. Adult males average four feet in length, with the tail, weighing 20 to 28 pounds. Females are somewhat smaller.
Seldom seen, they are relatively common in fresh water, such as this one in the Moose River, and in open waters on the coast, avoiding polluted areas. Otters seek ice-free waters in winter.
Powerful swimmers, river otters feed on slow moving fish. They can smell concentrations of fish in ponds that drain into small, slow moving streams and will follow that smell to the prey. Freshwater shellfish, amphibians, beetles, birds, bird and fish eggs, and muskrats, mice and young beavers are also on the menu.
In late winter, water levels usually drop below ice levels in rivers and lakes, leaving a layer of air that allows them to travel and hunt.
Den sites include hollow logs, log jams, piles of driftwood or boulders, and abandoned lodges and bank dens made by beaver. Well hidden, they are at the water’s edge with an entry just below the surface.
Essentially safe from predators while in water, river otters are vulnerable when they travel on land. Humans trap river otters to obtain their pelts, control fish predation in private ponds and commercial fish hatcheries, and prevent damage to private property.
Reduced water quality and development that destroys stream-bank habitat are threats to otter survival.
Text is condensed from
Link, Russell. “River Otters.” Maine. Department of Inland Fisheries and Wildlife. Augusta, Me. 2004. http://www.maine.gov/ifw/wildlife/human/lww_information/otters.html (accessed November 28, 2013)
Visit this site for more detailed information and additional resources on the River Otter.