River Otters can be foundthroughout the North American continent, from as far north as the Yukon and Northwest Territories to as far south as Mexico's Rio Grande and Colorado river deltas. In Canada, they can be found in every Province and Territory, though they have only returned to PEI during the early 1900's after being extripated from that province. As an aquatic mammal, Otters are often found in habitats with a sufficient amount of water; this can include Wetlands (Marshes, Swamps, Bogs, etc.), River networks, Lakes, and coastal Estuary systems. Otters will avoid any water systems that are exposed to pollution.

River Otters are carnivores, consuming a vast array of animals including fish, crustaceans, frogs, reptiles and birds, in addition to the eggs of the latter example. On rare occasions, Otters will take down mammalian prey or consume plant material.

River Otters reach Sexual Maturity between 2 to 3 years of age and will breed during the late winter months into the early spring season, after which the male will leave the female to birth and raise the pups on her own. While the Gestation period is only two months, female otters will employ a process called delayed implantation, rendering the fertilized embryo dormant for up to a year. From there, the Female Otter will give birth to an average of two to three pups between the months of November to May, but can birth as few as a single pup and as many as six. The pups are born blind and shelter in their mother's den for the first month of their lives. After two months, their mother teaches them how to swim. The pups are weaned off of their mother's milk at three months, and will begin to venture off on their own by half a year to a year in age. The lifespan of an otter in the wild is usually 8 to 9 years, but those in captivity can live for up to 21 years. Otters will utilize natural hollows or abandoned dens near river banks as a means of shelter, and will ensure that the den has an underwater entrance. The most common predators of Otters are Bobcats and Canids such as Coyotes and Wolves. Larger Bird of Prey Species can also hunt down Otters, and Alligators can predate Otters in their more southern range

As aquatic mammals, they have a thick, waterproof coat for insulation while in the water as well as for winter conditions, and they have webbed feet allowing for efficient swimming. They can plug up their nostrils and ears while submerged, and also possess a clear third eyelid known as a nictitating eyelid, which protects their eyesight while diving and swimming. They sport a long set of whiskers (vibrissae) that aid in detecting prey hidden in the substate of the water bodies that they swim in. Otters have multiple methods of communication, including audible methods (whistling, growls and screams), scent marking with their scent glands and visual/tactile methods such as touching and body posturing. Otters posses an extremely high metabolism, and as a result requires a constant supply of food to hunt and forage for