About North American River Otters
The North American river otter is a member of the weasel family. It is very well adapted to life in water. Otters have short powerful legs with webbed feet. They have a streamed-lined body that is about 2.5 feet long and a tail that is flattened and well-muscled. The tail is important in swimming and makes up about half of the otter's body length. On average otters weigh about 20 pounds. When in water, the otter's nostrils and ears can be closed. They can stay underwater for 6-8 minutes before they need to surface for another breath of air.
The dorsal side of the otter's fur is dark brown and the ventral side is light yellow. This is a color adaptation that is known as counter-shading. If a predator is above the otter, when it looks down, the otter blends in with the dark bottom. If a predator is below the otter, when it looks up, the otter blends in with the bright light from above. Otters have both coarse guard hairs and a thicker undercoat. This undercoat helps to waterproof them and keep them warm because it does not have a blubber layer.
Otters prefer the aquatic habitat, but they also roam on land. When alarmed, however, they make a mad dash for the water. Otters are nocturnal (active at night), but may also be crepuscular (active at both dusk and dawn). River otters are highly social animals and live in groups primarily made up of adult females and their pups. There are also groups consisting of individual males.
North American River Otters in the Wild
Otters are usually found no more than a few hundred meters from water. Most species are entirely dependent on aquatic habitats for food.
Native throughout the United States and Canada
River otters primarily eat fish, however they are opportunistic and will also eat crustaceans, mollusks, insects, birds, small mammals and frogs. Prey is captured in the mouth and eaten right away.
Currently they are listed as a species of “least concern” on the IUCN Red List. There numbers are not declining at a rate that would classify them as threatened.
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