Breeding

Mating takes place throughout the year after an elaborate courtship. Pregnancy lasts 8 or 9 months before the single pup is born well-formed, with its eyes open and a complete set of milk teeth. Although the birth takes place ashore, the mother immediately carries the pup into the water and from then on gives it constant attention, nursing and grooming it on her chest as she swims on her back. Pups do not leave their mother until they are about a year old, and do not breed until they are three years old. Females can bear pups only every other year, so sea otters are slow breeders.

A sea otter herd can make for noisy neighbours, as all sea otters are quite vocal. Pups cry when they are hungry, females coo affectionately to their pups and their mates and adults of both sexes scream when in distress. Companionship is expressed by a loud squeal which sounds rather like a whistle.