Marine Otter Social Behaviors

There is much to learn about the marine otter’s behavior. Tagged animals have been tracked over time, so some of how and why they behave the way they do is beginning to be understood. It is important to understand that each marine otter has its own personality, so there may be some differences. Some are anxious around humans, while others look upon this as an opportunity to play and show off.

It is common to find marine otters in groups along shorelines. These groups are called rafts and a raft may consist of just a few to up to thousands. Although this shows that marine otters like to be social, they also enjoy solitary time. They will usually mate, give birth and eat away from other otters.

Within a raft, otters form smaller groups, such as a mother pup pair or a small group of juvenile or adult males. The males are territorial; however the length of time they remain this way can vary from seasonal to an entire year. The male marine otters become sexually mature at five years of age and the territorial behavior begins showing up three to five years later.

The female is responsible for the pup so the mother pup pairing is an important social bond. The mothers teach pups the skills that are needed for growing up such as grooming and foraging. At three and a half months pups can usually swim on their own, can dive and groom without mother’s assistance. They are usually weaned between six months and one year.

Marine otters do not migrate over great distance like some other marine mammals. The territorial males may travel as far as 40 to 60 miles but otherwise otters stay close to their home shore.

These otters use vocalization and visual behaviors to communicate. Commonly a jerk of the head may be used when an individual otter comes up to a raft of marine otters. The approaching will use this behavior plus sniffing and nosing as they come near. It is unclear if this is a method used for greeting or for getting information on the raft through their olfactory senses. If the otter is an intruding one it may become aggressive and pounce and lunge at others.

One of the vocalization sounds marine otters use is a squeal by sea otter pup when exploring away from the shore. This sound allows the mother otter to find the pup when she finishes foraging. Marine otters have also been known to coo, whistle, shine, scream, hiss, grunt and growl. Grunting and cooing are usually done when the marine otter is eating. In addition mother pup pairs will also coo to each other. When under stress these otters will whine, hiss or growl.

These unique marine animals are fascinating for scientists to study and more is being learned about them all the time.