Endangered
Sea otter
Enhydra lutris
Adult sea otters typically weigh between 14 and 45 kg (30–100 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals.
Appearance
Unlike most other marine mammals, the sea otter has no blubber and relies on its exceptionally thick fur to keep warm. With up to 150,000 strands of hair per square centimetre (970,000/in2), its fur is the densest of any animal. The fur consists of long, waterproof guard hairs and short underfur. The guard hairs keep the dense underfur layer dry.
The sea otter is one of the smallest marine mammal species.
Male sea otters usually weigh 22 to 45 kg (49–99 lb) and are 1.2 to 1.5 m (47–59 in) in length, though specimens up to 54 kg (119 lb) have been recorded.
Published measurements include mass about 45 and length about 148.
Range and habitat
The sea otter is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Although it can walk on land, the sea otter is capable of living exclusively in the ocean. The sea otter inhabits nearshore environments, where it dives to the sea floor to forage.
A subsequent international ban on hunting, sea otter conservation efforts, and reintroduction programs into previously populated areas have contributed to numbers rebounding, and the species occupies about two-thirds of its former range. The recovery of the sea otter is considered an important success in marine conservation, although populations in the Aleutian Islands, in California, and in Russia have recently declined or have plateaued at depressed levels.
Habitat labels include coastal margin.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
It has a period of foraging and eating in the morning, starting about an hour before sunrise, then rests or sleeps in mid-day. Foraging resumes for a few hours in the afternoon and subsides before sunset, and a third foraging period may occur around midnight.
Females with pups appear to be more inclined to feed at night. Observations of the amount of time a sea otter must spend each day foraging range from 24% to 60%, apparently depending on the availability of food in the area. Sea otters have been seen mating throughout the year, but peak breeding periods have been observed in summer and early autumn.
In crisis
Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals living in a fraction of their historic range. The sea otter population is thought to have once been 150,000 to 300,000, stretching in an arc across the North Pacific from northern Japan to the central Baja California Peninsula in Mexico. Population estimates made between 2004 and 2007 give a worldwide total of approximately 107,000 sea otters.
The Exxon Valdez oil spill of 24 March 1989 killed thousands of sea otters in Prince William Sound, and as of 2006, the lingering oil in the area continued to affect the population. The population of sea otters in California has risen to around 3,000 in the wild.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Sea otter is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Sea otter, Wikidata item Q41407. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
