Patagonian Sea Lions

Theme area:  Sea Lion Rock
Scientific name:  Otaria byronia
Class:  Mammals
Order:   Carnivores
Suborder:   Pinnipeds
Family:   Otariidae
Continent:  South America
Habitat:  Coastal marine habitats and rockeries
Diet:  Piscivore
Weight:  130 - 350 kg
Size:  1.5 - 2.6 m
Covid Info
European Ex-situ Programme (EEP)

European Ex-situ Programme (EEP)

As is often the case with sea lions, this species exhibits marked sexual dimorphism.  Males bear a mane which is what earned them their common name, "sea lion".



As is often the case with sea lions, this species exhibits marked sexual dimorphism.   Males can reach up to 2.6 m in length and weigh between 300 and 350 kg. They have a large mane from which they get their name.  They reach sexual maturity between 4 and 7 years of age, but will not be able to defend their harem until they are 9-11 years old. Females can reach up to 1.5 to 2 m in length and weigh 130 to 170 kg.  They are sexually mature between 4 and 5 years of age.  At birth, the pup weighs between 10 and 15 kg and is 75 to 85 cm long. Lifespan is estimated at 20 years.



The Patagonian sea lion is found along much of the coast of South America. Its range extends down from northern Peru to Cape Horn and up the east coast to southern Brazil.



It mainly lives in coastal areas and the continental shelf.  It rarely ventures into deeper waters.



This species is rather sedentary and polygamous; the harem is generally made up of one male for every 4 to 10 females.  The male arrives on the beach about two weeks before the females.  He defends his territory in two different ways depending on the topography of the place.  If the beach has corners, the male will block the exit of females or the entrance of competitors with vocalisations, postures and battles.  Alternatively, if the beach is a long strip of land/sand, the male's strategy is to keep the females away from the water by pacing the area between the ocean and the beach.  Two to three days after their arrival, the females give birth to the young they have carried for a year.  Six days after giving birth, they ovulate and mate again.  Then, they start alternating 1 to 4 days at sea for hunting, with 2 days on land for nursing, until the pup is between 8 and 10 months.



The Patagonian sea lion is an opportunistic hunter.  It consumes a wide variety of fish depending on the area where it lives.  A large male may also feed on young elephant seals or young South American fur seals (a smaller species than the maned sea lion).



Killer whales, sharks and leopard seals.



Following several hundred years of hunting by humans for its fur and oil, the Patagonian sea lion population has greatly diminished. Nowadays, voluntary culls by fishermen, or accidental entanglement in trawler nets, continue to greatly reduce the numbers, especially around the Falkland Islands (Malvinas) where intensive fishing is practiced.



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Extinct in the wild
Critically endangered
Near threatened
Least concern
Insufficient data
Not evaluated


Between February and March each year, the Valdes Peninsula in Argentina is the scene of some impressive hunting displays. Patagonian sea lion pups gather in a nursery while their mothers are out hunting at sea.