South American Sea Lion

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Otaria redirects here. If you are looking for the continent in Magic: The Gathering, see Otaria.

South American Sea Lion

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Pinnipedia
Family: Otariidae
Subfamily: Otariinae
Genus: Otaria
Péron, 1816
Species: O. flavescens
Binomial name
Otaria flavescens

The South American Sea Lion or Southern Sea Lion (Otaria flavescens, formerly Otaria byronia) is a sea lion found on the Chilean, Peruvian, Uruguayan and Argentine coasts. It's scientific name was subject to controversy, with some taxonomists referring to it as Otaria flavescens and other referring to it as Otaria byronia. The former eventually won out.

Contents

[edit] Physical description

Adult male South American sea lion at Falkland Islands
Adult male South American sea lion at Falkland Islands

The South American sea lion is perhaps the archetypal sea lion in appearance. Males have a very large head with a well developed mane making them the most lionesque of the eared seals. They are twice the weight of females.[1] Both males and females are orange-coloured with upturned snouts. The manes on males are lighter than females, and female fur on the head and neck is lighter than that of males. Pups are born black or dark brown and molt into a more chocolate colour. The South American Sea Lion's size and weight can vary quite a lot. Adult males can grow up to 2.6 m (8 ft 6 in) and weigh up to 300 kg (660 lb). Adult females grow up to 1.8–2 m (6–7 ft) and weigh about half the weight of the males, around 150 kg (330 lb). These sea lions are the most sexually dimorphic of the five sea lion species.

[edit] Foraging

South American sea lions feed on a variety of fish including Argentine hake and anchovies. They also eat cephalopods, such as shortfin squid, Patagonian squid and octopus. They have even been observed preying on penguins and young South American Fur Seals. South American sea lions normally hunt in shallow waters less then five miles from shore. They often forage at the ocean floor for slow moving prey but they will also hunt schooling prey in groups. When captured, the prey is shaked violently and torn apart. The sea lions themselves are hunted by orcas, sharks and cougars.

[edit] Lifestyle and reproduction

Mother sea lion and pup
Mother sea lion and pup
South American sea lions basking at Islas Ballestas
South American sea lions basking at Islas Ballestas

South American sea lions prefer to breed on beaches made of sand, but will breed on gravel, rocky or pebble beaches as well. They can also be seen on flat rocky cliffs with tidepools. Sea lion colonies are more scattered on rocky beaches than sand, gravel or pebble beaches. The colonies make spaces between each individual when it is warm and sunny.

Mating occurs between August and December and the pups are born between December and February. Breeding groups can consist of up to 18 females with one to several males. Males maintain their boundaries by barking, roaring and other vocalizations. The males herd the females into their territories and prevent them from leaving until mating is over. The number of actual fights between males occurs depending on the number of females in heat.

During the breeding season, group raids will happen and are mostly caused by gangs of subadult males attempting to mate with the females. These raids cause choas in the beeding harem, spliting mothers from young. The resident males are unable to fought off all the raiders and keep all the females in their territorial boundaries.

South American sea lions at harbour in Mar del Plata
South American sea lions at harbour in Mar del Plata

Nevertheless subadult males are often unsuccessful securing a female. Sometimes an invading male will abduct pups possibly as an attempt to control the females. Pups are often severely injured or killed when this happens.

Female sea lion mothers have a routine of taking trips back into the sea for food and come back to nurse the pups. Pups first enter the water at about 4 weeks and are weaned at about 12 months. This is normally when the mother gives birth to a new pup.

[edit] Conservation

South American sea lions were greatly hunted in the 19th and 20th centuries. The hunting has since gone down and the species is no longer threatened and is protected in most of its range. However, they have declined in numbers in the Falkland Islands and they still are killed due the sea lions' habits of stealing fish and damaging fishing nets. Sea lions are important to the country.

[edit] References

  1. ^ Kindersley, Dorling (2001,2005). Animal. New York City: DK Publishing. ISBN 0-7894-7764-5.