Otters

North American River Otter (Lutra or Lontra canadensis)
North American river otters are semi-aquatic mammals, with long, streamlined bodies, thick tapered tails, and short legs. Their fur is a dark brown to black that is very dense to keep them warm in the water. Their feet are clawed and webbed. The animals are known to be playful, fast on land, and excellent swimmers. They can stay underwater for up to 8 minutes. They usually hunt at night but can be seen at all times of the day.
The river otter can be found across the United States and Canada. They can be found in many bodies of water, preferring those with steeper banks that they can find dens in for shelter as long as there is food available. The dens have underwater entrances that lead to nest chambers lined with leaves, grass, moss, bark, and hair. Otters eat fish, amphibians, and crustaceans, small mammals, mollusks, reptiles, birds and fruits if they can find them. They live to be about 13 years old in the wild.
Male and female otters do not associate except during breeding season. Young are born in litters of 1-6 kits at a time. They are born with fur but otherwise helpless. They become old enough to leave their mothers anywhere between 6 months to a year. They are sexually mature at 2-3 years of age.

The river otter is currently listed as a species of Least Concern due to the fact that populations have stabilized due to improvements in water quality, management of harvesting for fur and reintroduction programs in many states.