South American Sea Lion

The South American sea lion (Otaria flavescens, formerly Otaria byronia), also called the southern sea lion and the Patagonian sea lion, is a sea lion found on the Chilean, Peruvian, Uruguayan, Argentine and Southern Brazilian coasts. It is the only member of the genus Otaria. Its scientific name was subject to controversy, with some taxonomists referring to it as Otaria flavescens and others referring to it as Otaria byronia. The former eventually won out. Locally, it is known by several names though the most common ones are lobo marino (sea wolf) and león marino (sea lion).

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. Both males and females are orange or brown 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 greyish orange ventrally and black dorsally and moult into a more chocolate colour.

The South American sea lion's size and weight can vary considerably. Adult males can grow over 2.73 m (9 ft) and weigh up to 350 kg (770 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.

As its name suggests, the South American sea lion is found along the coast and offshore islands of South America. It ranges from Peru south to Chile in the Pacific and then north to southern Brazil in the Atlantic. It generally breeds in the southern part of its range and travels north in winter and spring. Notable breeding colonies include Lobos Island, Uruguay; Peninsula Valdes, Argentina; Beagle Channel and the Falkland Islands. Some individuals wander as far north as southern Ecuador, although apparently they never bred there.

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. They can also be found in marinas and wharves but do not breed there.

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, pelicans and young South American fur seals. South American sea lions normally hunt in shallow waters less than 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 shaken violently and torn apart. South American sea lions have been recorded to take advantage of the hunting efforts of dusky dolphins, feeding on the fish they herd together. The sea lions themselves are preyed on by orcas and sharks.

See also :

• Social behavior and reproduction.
• Human interactions