The Otters

Otters are members of Mustelidae, the weasel family. They are highly inquisitive predators with voracious appetites and rapid metabolisms. Like their cousins—such as weasels, ferrets—most otters have a pair of scent glands at the base of the tail, which they use for scent marking their territories. However, otters differ from their land-dwelling cousins in a very important way: they are specially adapted for life in the water.

The bodies of otters are generally long and slender, with flattened tails that they use like a rudder to steer through the water. They all have webbed hind feet and most have webbing on the front feet, making them very strong and agile swimmers. For the most part, otters divide their time between the land and the water. They are very opportunistic predators and they will occasionally take prey such as insects and small mammals while on land. However, otters do the bulk of their hunting underwater, coming ashore only to rest, mark their territories, or care for their young.

photo M Noonan

The water in which otters feed is often very muddy or dark, making hunting by eyesight difficult at best. To cope with these conditions otters have stiff whiskers, called vibrissae, around their faces and on their elbows. The vibrissae help otters feel the vibrations caused by swimming prey, allowing them to track fish, frogs or crustaceans in water that is murky or deep.

These waters may also be fairly cold, and (unlike marine mammals like seals and whales) otters do not have a layer of blubber to keep them warm.  Instead, otters fluff their fur with their paws to trap air in their thick coats. The trapped air acts as insulation from the cold.

The thirteen species of otter have a nearly global distribution and can be found on every continent except Antarctica and Australia. The populations of each species are tracked by the World Conservation Monitoring Centre, and many species are listed as vulnerable or endangered. The greatest threats to otters come from humans, either through habitat loss or by chemical pollution of the waterways in which the otters live


Content provided by Canisius College students under the direction of Michael Noonan, PhD.