common name
sea otter

California sea otter: Enhydra lutris nereis
Alaskan sea otter: Enhydra lutris kenyoni
Russian sea otter: Enhydra lutris lutris

maximum weight of 45 kg.

males: 10 to 15 years; females: 15 to 20 years

the otter's 'whine' and 'squeal' that is commonly heard during courtship has been found to consist of graded signals that vary over a continuum

there is a degree of complexity and richness of communication patterns believed to have evolved as a result of complex social relationships

a coat of darkly colored (shades of brown), sparse guard hair and dense insulating fur that traps air and prevents water from contacting the skin

flattened hind feet or flippers for propulsion

retractile claws on the front feet

a loose flap or pouch of skin under each foreleg which is used to hold food items gathered from the sea bottom

flattened, rounded molar teeth with no cutting cusps

a horizontally flattened tail that aids in propulsion

a manner of swimming underwater by means of vertical undulations of the hind flippers and tail

an external ear that resembles the ear of an otariid more than that of its closest relative, the river otter

when resting, sea otters often lie on their backs among kelp or in quiet water

the most common position is with the head up, and with folded paws and chin resting on the chest

British Columbia: 2,500-3,000 sea otters. The population increase in B.C. has slowed in recent years as because some parts of the population appear to be at equilibrium.

Russia: 13,000 sea otters

Alaska: approximately 60,000-90,000 sea otters; California: 2,000 sea otters;
Washington: 800

nearshore coastal waters of less than 54 m in depth

fish and marine invertebrates, including various species of mussels, tunicates, sea stars, bivalves, crabs, abalone and octopus.E. lutris demonstrates significant selectivity and intelligence when foraging and consuming its prey

otters can detect and avoid toxic shellfish if suitable low toxicity prey are available

Otters are often observed using rocks to pound small, hard bodied prey items to gain access to the edible fleshy interior

mating tends to be prolonged and aggressive

mating is aquatic and often involves violent and prolonged copulations during which the male approaches the female from behind and grasps her face and nose with his teeth, sometimes pulling her head underwater while attempting to subdue her

Some females may form pair bonds with a single male while others may mate with up to three different males during a single estrous period

most females reach sexual maturity between 2-5 years of age, with 88% maturing by age 4

most females have been observed to have the first pup by 3-4 years of age

reproductive rate is maximal at 5 years of age and remains stable through to age 15

female otters typically mate numerous times during their estrous period, which lasts several days and occurs about once each year

if a female loses her pup before weaning age, she may enter estrus and mate repeatedly two or more times in a single year

mean gestation period is approximately 218 days; mean pup dependency period is about 153 days

the majority of pups are born in spring (February) and early summer

groups of females periodically bring their young pups ashore to rest in a process known as hauling

female reproductive rates and pup survivorship are generally higher in undisturbed areas with abundant food resources

threatened in 1996 by the Committee of the Status of Endangered Wildlife in Canada (COSEWIC) and through the B.C. Wildlife Act

protected by the federal government’s Canada Fisheries Act and the B.C. Wildlife Act

California population is protected by the Marine Mammal Act and the U.S. Endangered Species Act