The South American Sea Lion is found from Peru through to Cape Horn and the entire Atlantic Coast through to the South of Brazil. Its total population is estimated at 250.000 animals.
They are large otariidae with great sexual dimorphism. The babies are born weighing 11-15kg and 75-85cm in length and are black on top and paler underneath. They shed their fur for the first time at two months of age, becoming dark brown. Sexual maturity arrives at 4 years of age in females and 5-6 years of age in males. The mating season varies depending on the latitude. In most breeding locations both sexes begin to arrive on the beaches around the middle of December although the majority arrive mid to end of January.
Females tend to give birth two or three days after their arrival. The females go into oestrous six-twelve days after the birth and the majority of them enter the water for the first time after the birth in order to eat two-three days after the oestrous. The pups are weaned at 8-10 months and all this time the mothers come and go from the sea, taking up to four days to return and suckle their babies. This species of sea lion is considered to be non-migratory as the majority of the rockeries where they live remain inhabited all year round, although they can cover large distances outside of the breeding season.
They feed from a wide range of prey depending on their location, they are quite opportunistic. More than 40 types of animals have been identified in their stomachs, everything from all types of fish to crustaceans or sponges. The females tend to prey more on benthonic species (that live on the seabed) while the males mainly eat pelagic species (live swimming). Immersions are quite long and can last up to 7 minutes and they are capable of diving to more than 100 metres depth.
Their natural predators are orcas, sharks and leopard seals and possibly also the puma. In the already infamous Northern Point of the Valdez Peninsula the orcas surf the waves to partially beach themselves and reach the sea lion babies on the sea shore.