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Eumetopias jubatus

(Steller's sea lion)

Overview

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Endangered

Threat status

Interesting Facts

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Common Names

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Click on the language to view common names.

Common Names in Danish:

Stellers søløve

Common Names in Dutch:

Stellerzeeleeuw, Zeeleeuw

Common Names in English:

northern sea lion, Northern sealion, Sea king, stellar sea lion, Steller Sea Lion, steller sealion, Steller's sea lion, Steller's sealion

Common Names in French:

Lion de mer à crinière, Lion de mer Steller, Otarie à crinière

Common Names in German:

Stellers Seelöwe, Stellerscher Seelöwe

Common Names in Italian:

Leone marino di Steller, Otaria

Common Names in Portuguese:

Leão marinho de juba

Common Names in Russian:

Сивуч (северный морской лев)

Common Names in Spanish:

Léon de mar

Description

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Habitat

Typically found in water with a depth of 0 to -100 meters (0 to -328 feet).[1]

Ecology: Steller Sea Lions are the largest otariids and the fourth largest pinniped. Both sexes are robust and powerfully built at all ages. They are sexually dimorphic , with adult males weighing three times as much, and growing 20-25% longer than adult females. Pups are born with a thick blackish-brown lanugo that is moulted by about 6 months of age. The maximum length of adult males is about 3.3 m and average weight is 1000 kg . The maximum length for adult females is about 2.5 m and average weight is 273 kg. Pups are born at an average of about 1 m and 18-22 kg.

The age of maturity is 3-6 years for females, and 3-7 years for males (Calkins and Pitcher 1982). Males are not able to defend territories before they are 9 years old (L. Lowry pers. comm. ). The annual pregnancy rate of mature females declined during the 1970’s and 1980’s and was estimated to be 55% in the 1980’s based on collections at sea (Pitcher et al. 1998). Recent age-structured modelling based on population counts from the central Gulf of Alaska indicates that the birth rate in 2004 was 36% lower than in the 1970’s (Holmes et al. 2007). Gestation lasts one year, including a delay of implantation of about 3 months. Females may live up to 30 years old and males to about 20 years (Reijnders et al 1993).

Steller Sea Lions are highly polygynous and breed in the late spring and summer. Adult males arrive before females and those that are nine years or older establish themselves on territories, which they aggressively and vociferously defend. Steller sea lions have deep voices and produce powerful low-frequency rolling roars and can be heard for long distances over the noise of wind and waves.

Pups are born from May through July, and females stay continuously ashore with their newborns for the first week to ten days after giving birth. Following this period of attendance, females make foraging excursions, primarily at night for periods of 18-25 hours, followed by time ashore to nurse their pup. Females come into estrous and mate about two weeks after giving birth. Weaning can occur before the next breeding season , but it is not unusual to see females nursing yearlings or older juveniles .

Throughout their range , Steller Sea Lions are primarily found from the coast to the outer continental shelf and slope . However, they frequent and cross deep oceanic waters in some parts of their range. Steller Sea Lions occasionally leave haulouts in very large groups; however, sightings at sea are most often of groups of 1-12 animals. They aggregate in areas of prey abundance , including near fishing vessels , where they will feed on netted fish and by-catch . Steller sea lions are known to haulout on sea ice.

They are not considered migratory; juveniles and subadults make the longest distance trips. Adults usually forage and live near their natal colonies and return to these sites to breed. The area used by adult females for foraging in winter increases dramatically over the area used in the summer and females tend to dive deeper in winter than summer. Diving is generally to depths of 200 m or less and dive duration is usually two minutes or less, with both parameters varying by season and age of the animal Diving ability of pups and juveniles increases with age, and they routinely dive to depths of around 140 m for periods of two minutes as yearlings. The diving of adult males has not been studied.

Steller Sea Lions feed on many varieties of fish and invertebrates . Much of the information on diet comes from animals living in Alaska, where Steller Sea Lions feed on walleye pollock, Pacific Cod , Atka Mackerel , herring , sand lance, several varieties of flatfish , salmon and rockfish, and invertebrates such as squid, octopus , bivalves and gastropods (Sinclair and Zeppelin 2002, Trites et al. 2007). Adult females with young pups feed extensively at night, switching to foraging at any time after the breeding season. Steller sea lions are known to kill and consume young and small northern fur seals at the Pribilof Islands, and also have been reported to kill and consume Harbour and Ringed seals, and possibly Sea Otters.

The primary predators of Steller Sea Lions are Killer Whales . Sleeper Sharks in Alaska have been found with Steller Sea Lion remains in their stomachs, but it is unknown whether the prey was scavenged and in any case they are not believed to be primary predators. Great White Sharks presumably take Steller pups within the areas where their range overlaps.[2].

List of Habitats :

Taxonomy

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Synonyms

Arctocephalus monteriensis Gray • Otaria stellerii Lesson • Phoca jubata Schreber

Notes

Name Status: Accepted Name .

Last scrutiny: 15-Aug-2007

Similar Species

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Members of the genus Eumetopias

ZipcodeZoo has pages for 2 species and subspecies in this genus:

E. jubata (Steller Sea Lion) · E. jubatus (Steller's Sea Lion)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal February 29, 2008:

Identifiers

Footnotes

  1. Mean = 28.680 meters (94.094 feet), Standard Deviation = 45.760 based on 128,850 observations. Ocean depth information for each observation from British Oceanographic Data Centre. [back]
  2. Gelatt, T. & Lowry, L. 2008. Eumetopias jubatus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 01 February 2012. [back]
Last Revised: 7/14/2012