North American river otters, Acadia National Park, Maine, USA

© George Sanker/Minden Picture

North American river otters

The creatures in today’s photo are a pair of North American river otters swimming in Maine’s Acadia National Park. Technically members of the weasel family, these “water dogs” can also be found in waterways and along the coasts across North America. A myopic animal with eyesight adapted to assist with swimming, river otters aren’t afraid to approach humans or boats.

They’re active year-round, though they tend to do most of their business at night, which primarily consists of hunting and eating. River otters are highly active predators, usually going after fish but they have been known to munch on fruit, reptiles, ducks and even the rare beaver. River otters are highly sensitive to pollution, so will tend to disappear from tainted areas. Scientists revere them as trusted bioindicators of the environments where they live due to the way their bodies accumulate various chemical compounds.