Animal Diversity Web

Ge­o­graphic Range

Gala­pa­gos sea lions are found scat­tered amongst the Gala­pa­gos Arch­i­pel­ago, which con­sists of is­land clus­ters po­si­tioned di­rectly west of Ecuador. These sea lions re­side on all the main is­lands, rocks, and other diminu­tive is­lands of this arch­i­pel­ago. Some are also found rang­ing along Ecuado­rian north coast to Isla Gorg­ona of Co­lum­bia. In 1986, a group ar­rived at Isla de la Plata near the shores of Ecuador. Some were even spot­ted 500 km south­west of Costa Rica on Isla del Coco. (Halpin, et al., 2009)

• Biogeographic Regions
• pacific ocean
  • native

Habi­tat

Male Gala­pa­gos sea lions can usu­ally be found in­land where abun­dant shade is pre­sent, while fe­males oc­cupy dif­fer­ent habi­tats de­pend­ing on the age of their pups (Wolf et al., 2005). Dur­ing the day, sea lions can be found on beaches near the water, which they enter through­out the day. At night, they move higher on the beach. En­ergy costs of lo­co­mo­tion and ther­moreg­u­la­tion con­tribute to habi­tat use; Gala­pa­gos sea lions most fre­quently oc­cupy areas neigh­bor­ing the sea that have ad­e­quate lev­els of shade, flat, un­com­pli­cated ter­rain, and nearby tide pools. Habi­tat usage also varies with ma­tu­rity level and sex dur­ing the re­pro­duc­tive pe­riod, in which sex­ual sep­a­ra­tion oc­curs (Wolf et al., 2005). (Orr, 1967; Wolf, et al., 2005)

• Habitat Regions
• saltwater or marine

• Aquatic Biomes
• temporary pools
• coastal
• brackish water

• Range depth

  186 (high) m

  610.24 (high) ft

• Average depth

  37 m

  121.39 ft

Phys­i­cal De­scrip­tion

Gala­pa­gos sea lions dif­fer in color de­pend­ing on sex and whether their coats are wet or dry. The area sur­round­ing the eyes as well as the muz­zle of both males and fe­males are lighter in hue than the rest of the body. After being sub­merged in water, the bull's coat takes on a dark black hue. When dry, the coat is usu­ally dark brown but can range from dif­fer­ent shades of brown to gray. Once a bull reaches full ma­tu­rity, the coat ceases to get any darker, and its back usu­ally turns a light shade of gray. Ma­ture fe­males, ado­les­cent males, and ju­ve­niles vary in shade from light brown to tan. Pups ex­pe­ri­ence their ini­tial molt around five months of age, los­ing the darker coat they were born with. (Halpin, et al., 2009)

Gala­pa­gos sea lions are sex­u­ally di­mor­phic, with males larger than fe­males. Males tend to have a thicker, stouter neck, shoul­ders and chest than fe­males, and adult ca­nines are sub­stan­tially larger and stronger in males. As males grow, their sagit­tal crest de­vel­ops more rapidly, leav­ing a pro­nounced pro­tru­sion on their head. After the male reaches full ma­tu­rity, the crest ceases to grow, and its fore­head be­comes steeper due to the pro­nounced ridge that forms at the back of its eyes. Fe­male Gala­pa­gos sea lions have a more elon­gated, sleek neck and a wider upper body rel­a­tive to their body size. Fe­males, along with im­ma­ture sea lions, do not have sagit­tal crests; their fore­head is less de­fined and ado­les­cents fore­heads are al­most nonex­is­tent, with vir­tu­ally a flat head. Gala­pa­gos sea lions can weigh be­tween 50 and 250 kg and are often 150 to 250 cm in length. ("Gala­pa­gos Sea Lion", 2006; Halpin, et al., 2009)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• sexes shaped differently

• Range mass

  50 to 250 kg

  110.13 to 550.66 lb

• Range length

  150 to 250 mm

  5.91 to 9.84 in

Re­pro­duc­tion

Sea lions in the fam­ily Otari­idae, in­clud­ing Gala­pa­gos sea lions, prac­tice polygamy. Lit­tle is oth­er­wise known re­gard­ing the mat­ing sys­tems of this species. (Orr, 1967; Orr, 1967)

• Mating System
• polygynous

Gala­pa­gos sea lions have a long breed­ing sea­son from May to Jan­u­ary, as wit­nessed by the great size vari­a­tion of Gala­pa­gos sea lions within the Gala­pa­gos Arch­i­pel­ago. Ges­ta­tion lasts 11 months, and sin­gle pup is born per fe­male dur­ing each breed­ing in­ter­val. Male and fe­male pups weigh about 6 kg when born, and they are weaned at 11 to 12 months of age. Gala­pa­gos sea lion pups are par­tially in­de­pen­dent be­tween 12 and 24 months, while still re­turn­ing to nurse from time to time (Au­ri­oles and Trillmich, 2008; Halpin et al., 2009; Orr, 1967). The age of sex­ual ma­tu­rity for both male and fe­male Gala­pa­gos sea lions is be­tween 4 and 5 years of age (Au­ri­oles and Trillmich, 2008). (Au­ri­oles and Trillmich, 2008; Halpin, et al., 2009; Orr, 1967)

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual

• Breeding interval

  Galapagos sea lions breed once yearly.

• Breeding season

  Galapagos sea lions breed between May and January.

• Average number of offspring

  1

• Average gestation period

  11 months

• Average weaning age

  11 to 12 months

• Average time to independence

  12 to 24 months

• Average age at sexual or reproductive maturity (female)

  4 to 5 years

• Average age at sexual or reproductive maturity (male)

  4 to 5 years

Mother Gala­pa­gos sea lions have a close bond with their pups. Moth­ers at­tend to their pups con­tin­u­ously for 6 to 7 days after birth, after which they feed in the sea, re­turn­ing at night to con­tinue feed­ing their young. Mother and pups rec­og­nize each other by their unique scent and vocal calls (Halpin et al., 2009). Fe­male sea lions nurse only one pup at a time, until they give birth to the next pup. Some fe­males allow both her year­ling and pup to nurse si­mul­ta­ne­ously. If the fe­male does not bare an­other pup, then the first can nurse for up to three years (Trillmich, 1981). (Halpin, et al., 2009; Trillmich, 1981)

• Parental Investment
• female parental care
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

Gala­pa­gos sea lions are es­ti­mated to live 15 to 24 years in the wild and 20 years on av­er­age (Au­ri­oles and Trillmich, 2008)

• Typical lifespan
  Status: wild

  15 to 24 years

• Average lifespan
  Status: wild

  20 years

Be­hav­ior

Gala­pa­gos sea lions are sex­u­ally di­mor­phic, and tend to live among so­cial groups of ap­prox­i­mately 30 in­di­vid­u­als (Wolf et al., 2005; "Gala­pa­gos Sea Lion," 2006), which con­sist of ma­ture fe­males, their young, and one dom­i­nant male. Dom­i­nant bulls are very ter­ri­to­r­ial, and when an in­truder is sighted, the bull takes im­me­di­ate ac­tion. He pa­trols back and forth in the water for most of the day, ag­gres­sively bark­ing to de­clare his ter­ri­tory (Orr, 1967). Males tend to hold their ter­ri­tory from 10 days to 3 months be­fore being dis­placed by an­other male. Bulls not dom­i­nat­ing a colony gather in bach­e­lor colonies ("Gala­pa­gos Sea Lion," 2006). (Orr, 1967; Wolf, et al., 2005)

Gala­pa­gos sea lions be­come ac­tive at the first sign of light, when the dom­i­nant bull first en­ters the water to feed fol­lowed by the rest of the group. The ma­jor­ity of their time in spent the water look­ing for food, and they fre­quently enter the water thrugh­out the day. They rarely travel be­yond 16 km from the shore and, under threat of preda­tors, they will flee from the water as quick as pos­si­ble and find safety on shore (Bar­low, 1974). The rest of the group's time is spent on the beach, where they care for the young and, dur­ing the breed­ing sea­son, cop­u­late. Males also enter the water to swim to a dif­fer­ent area in search of new mates. Gala­pa­gos sea lions tend to sleep through­out the night on higher beaches. Mem­bers of the group, es­pe­cially the bull, may sleep apart from each other. (Bar­low, 1974; Orr, 1967; Wolf, et al., 2005)

• Key Behaviors
• natatorial
• diurnal
• motile
• territorial
• social
• dominance hierarchies

Home Range

Lit­tle in­for­ma­tion is avail­able re­gard­ing the home range of Gala­pa­gos sea lions.

Com­mu­ni­ca­tion and Per­cep­tion

Dom­i­nant male Gala­pa­gos sea lions pa­trol their ter­ri­tory, ward­ing off in­trud­ers, often with a bark. Dom­i­nant bulls also touch the muz­zle of fe­males of in­ter­est (Orr, 1967). Mother and pups rec­og­nize each other by their unique scent and vocal calls (Halpin et al., 2009). (Halpin, et al., 2009; Orr, 1967)

• Communication Channels
• visual
• tactile
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• chemical

Food Habits

Gala­pa­gos sea lions usu­ally for­age at shal­low depths for fish, squid, oc­to­pus, and crus­taceans. They have been ob­served smash­ing oc­to­pus on the water's sur­face, al­low­ing for eas­ier con­sump­tion. Dur­ing El Niño of the 1980s, their pri­mary diet con­sisted of sar­dines and myc­tophids, or lantern­fish. ("Gala­pa­gos Sea Lion", 2006; Dellinger and Trillmich, 1999)

• Primary Diet
• carnivore
  • piscivore
  • molluscivore

• Animal Foods
• fish
• mollusks

Pre­da­tion

When in dan­ger, Gala­pa­gos sea lions flee from the water, seek­ing safety on on shore (Bar­low, 1974). Sea lion pups risk pre­da­tion from feral, wild dogs, which are ca­pa­ble of trans­mit­ting dis­eases to the sea lion pop­u­la­tion. Killer whales and sharks prey on sea lions; those sea lions that es­cape are often left with with scars and other in­juries (Halpin et al., 2009). (Bar­low, 1974; Halpin, et al., 2009)

• Known Predators

  • Sharks
  • Killer whales Orcinus orca
  • Dogs Canis lupus familiaris

Ecosys­tem Roles

Gala­pa­gos sea lions are mu­tu­al­ists with lava lizards on Bar­ring­ton Is­land. These lizards are at­tracted to the flies around the sea lions, and the lava lizards are often found rest­ing on or around Gala­pa­gos sea lions. Gala­pa­gos sea lions also trans­port nau­ti­cal nu­tri­ents into the ter­res­trial ecosys­tem, mov­ing nu­tri­ents in high con­cen­tra­tions to shore­line flora at low el­e­va­tions (Fariña et al., 2003). Ad­di­tion­ally, young Gala­pa­gos sea lion can catch dis­ease from fer­rel dogs, which also prey on young sea lions. (Fariña, et al., 2003; Orr, 1967)

• Ecosystem Impact
• creates habitat

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Gala­pa­gos sea lions may draw in tourists as they are en­demic to the Gala­pa­gos is­lands (Au­ri­oles and Trillmich, 2008). (Au­ri­oles and Trillmich, 2008)

• Positive Impacts
• ecotourism

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Gala­pa­gos sea lions on hu­mans.

Con­ser­va­tion Sta­tus

There are an es­ti­mated 20,000 to 50,000 in­di­vid­u­als of Gala­pa­gos sea lions found mainly in the Gala­pa­gos Arch­i­pel­ago. The arch­i­pel­ago is part of an Ecuado­rian Na­tional Park, which is en­closed by a ma­rine re­sources re­serve. Tourism of the park does per­sist largely, but is care­fully mon­i­tored to deter any dis­tur­bances (Halpin et al., 2009). El Niño of the early 1980’s greatly af­fected sea lion pop­u­la­tions, caus­ing dozens of year­lings to die, and de­creas­ing the pup fe­cun­dity for the fol­low­ing year (Tril­limich and Lim­berger, 1985). (Halpin, et al., 2009; Trillmich and Lim­berger, 1985)

• IUCN Red List

  Endangered
  More information

• IUCN Red List

  Endangered
  More information

• US Federal List

  No special status

• CITES

  No special status

Con­trib­u­tors

Kaila Huh­tasaari (au­thor), North­ern Michi­gan Uni­ver­sity, John Brug­gink (ed­i­tor), North­ern Michi­gan Uni­ver­sity, Gail Mc­Cormick (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

2006. "Gala­pa­gos Sea Lion" (On-line). The An­i­mal Files. Ac­cessed Jan­u­ary 27, 2011 at http://​www.​theanimalfiles.​com/​mammals/​seals_​sea_​lions/​galapagos_​sea_​lion.​html.

Au­ri­oles, D., F. Trillmich. 2008. "Za­lo­phus wolle­baeki." (On-line). IUCN Red List of Threat­ened Species.. Ac­cessed April 26, 2009 at http://​74.​125.​95.​132/​search?​q=cache:​HPbRfWi1D4wJ:​www.​iucnredlist.​org/​details/​41668+Zalophus+wollebaeki+longevity&​cd=1&​hl=en&​ct=clnk&​gl=us.

Bar­low, G. 1974. Gala­pa­gos Sea Lions are Pa­ter­nal. Evo­lu­tion, Vol. 28: 476-478. Ac­cessed Feb­ru­ary 02, 2009 at http://​www.​jstor.​org/​stable/​2407169?&​Search=yes&​term=lion&​term=sea&​term=Galapagos&​list=hide&​searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DGalapagos%2Bsea%2Blion%2B%26x%3D11%26y%3D12%26wc%3Don&​item=25&​ttl=400&​returnArticleService=showArticle.

Dellinger, T., F. Trillmich. 1999. Fish prey of the sym­patric Galápagos fur seals and sea lions: sea­sonal vari­a­tion and niche sep­a­ra­tion.. Cana­dian Jour­nal of Zo­ol­ogy, 77: 1204–1216. Ac­cessed Feb­ru­ary 08, 2009 at http://​rparticle.​web-p.​cisti.​nrc.​ca/​rparticle/​AbstractTemplateServlet?​calyLang=eng&​journal=cjz&​volume=77&​year=1999&​issue=8&​msno=z99-095.

Fariña, J., S. Salazar, K. Wallem, J. Wit­man, J. Ellis. 2003. Nu­tri­ent Ex­changes be­tween Ma­rine and Ter­res­trial Ecosys­tems: The Case of the Gala­pa­gos Sea Lion Za­lo­phus wolle­baecki.. Jour­nal of An­i­mal Ecol­ogy, Vol 72: 873-887. Ac­cessed Feb­ru­ary 02, 2009 at http://​www.​jstor.​org/​stable/​3505369?&​Search=yes&​term=%22Nutrient+Exchanges+between+Marine+and+Terrestrial+Ecosystems+The+Case+of+the+Galapagos+Sea+Lion+Zalophus+wollebaecki.​%22&​list=hide&​searchUri=%2Faction%2FdoBasicSearch%3FQuery%3D%25E2%2580%259CNutrient%2BExchanges%2Bbetween%2BMarine%2Band%2BTerrestrial%2BEcosystems%253A%2BThe%2BCase%2Bof%2Bthe%2BGalapagos%2BSea%2BLion%2BZalophus%2Bwollebaecki.​%25E2%2580%259D%2B%26x%3D0%26y%3D0%26wc%3Don&​item=2&​ttl=5&​returnArticleService=showArticle.

Halpin, A., P. Crow­der, B. Best, E. Fu­jioka. 2009. "Map­ping ma­rine mam­mals, birds and tur­tles." (On-line). OBIS SEAMAP. Ac­cessed Feb­ru­ary 08, 2009 at http://​seamap.​env.​duke.​edu/​species/​tsn/​622014.

Orr, R. 1967. The Gala­pa­gos Sea Lion. Jour­nal of Mam­mal­ogy, Vol 48: 62-69. Ac­cessed Feb­ru­ary 02, 2009 at http://​www.​jstor.​org/​stable/​1378170?&​Search=yes&​term=lion&​term=sea&​term=Galapagos&​list=hide&​searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DGalapagos%2Bsea%2Blion%2B%26x%3D8%26y%3D15%26wc%3Don&​item=6&​ttl=400&​returnArticleService=showArticle.

Trillmich, F. 1981. Mu­tual Mother-Pup Recog­ni­tion in Galápagos Fur Seals and Sea Lions: Cues Used and Func­tional Sig­nif­i­cance. Be­hav­iour, 78: 21-42. Ac­cessed Feb­ru­ary 08, 2009 at http://​www.​jstor.​org/​stable/​info/​4534129?​seq=1.

Trillmich, F., D. Lim­berger. 1985. Dras­tic ef­fects of El Niño on Gala­pa­gos pin­nipeds. Oe­colo­gia, 67: 19-22. Ac­cessed Feb­ru­ary 02, 2009 at http://​www.​springerlink.​com/​content/​p83r389p73017873/​.

Wolf, J., G. Kauer­mann, F. Trillmich. 2005. Males in the Shade: Habi­tat Use and Sex­ual Seg­re­ga­tion in the Galápagos Sea Lion (Za­lo­phus cal­i­for­ni­anus wolle­baeki). Be­hav­ioral Ecol­ogy and So­cio­bi­ol­ogy, Vol. 59: 293-302. Ac­cessed Feb­ru­ary 02, 2009 at http://​www.​jstor.​org/​stable/​25063702?&​Search=yes&​term=lion&​term=sea&​term=Galapagos&​list=hide&​searchUri=%2Faction%2FdoBasicSearch%3FQuery%3DGalapagos%2Bsea%2Blion%2B%26x%3D0%26y%3D0%26wc%3Don&​item=12&​ttl=400&​returnArticleService=showArticle.