Southern sea lion, Patagonian sea lion. Locally it is known as Lobo marino (es)/Lobo marinho (pt) (sea wolf) and León marino (es)/Leão marinho (pt) (sea lion)
Amongst pinnipeds, the winged-footed family, there are eared seals and true seals. The former are also known as fur seals and sea lions. The South American sea lion’s technical name is the Patagonian sea lion but this name is rarely used. When full grown the male sea lions are twice the weight of females and around their large heads is a patch of short hair similar to the beginnings of a lion’s mane. Males have a neck that is more muscled than that of females.
The South American sea lion lives along the South American coastlines on the Atlantic side from Rio de Janeiro to Perú on the Pacific side in southernmost South America. Some have been known to occur in the Falkland and Galapagos Islands. They live along shorelines and beaches, which usually consist of sand, rocks, gravel and/or pebbles. They also occur on flat rocky shelves or on cliffs with boulders and tide pools.
South American sea lions are a diurnal and social species which lives in groups usually consisting of multiple females with one or several males who defend their territory. Males, called bulls, patrol their range actively, threatening intruders, and advertising their territorial boundaries by means of vocalizations. Fights are, however, rare, unless an intruder attempts to take over the bull’s territory. His territory is very dependent on cows being present rather than its size or any topological features. Each bull usually has 18 cows within his territory. Younger males who do not yet have any mating females usually live in groups with 10 to 40 other young males, and try to raid the established territories of bulls to obtain females. South American sea lions generally hunt in shallower waters, less than five miles out from the shore. They hunt in groups when seeking prey that travel in schools.
This sea lion has a polygynous lifestyle. The mating season runs from early August until December, when males will defend their territories aggressively and show an interest in females. Mating behaviors include mutual vocalizations, mouth and snout contact, smelling, and some playful biting. Gestation is for about 11-12 months, and usually one pup is born. Mothers mate again soon after birth with the male whose territory the birth took place in. Pups spend most of the day in pods or groups playing, sleeping, or staying near the water. They first go into the water usually after about 3 to 4 weeks in a large group with other sea lions. Pups nurse for around 6 to 12 months, until their mother bears another pup, though some mothers nurse both pups at the same time. Male pups are sexually mature by 6 years of age, and females at 4, and both genders are full adult size at about 8 years of age.
The Southern sea lion has been killed in the past for the fur trade, causing a significant decrease in numbers. Today it is illegal in Argentina to kill sea lions but populations are still declining as a result of fisherman shooting sea lions that swim into their fisheries. Another threat is drowning in fishing nets.
South American sea lion is the most abundant marine mammal across its range. According to the IUCN Red List, the total South American sea lion population size is around 445,000 individuals, including approximately 222,500 mature individuals. Currently this species is classified as Least Concern (LC) and its numbers today remain stable.
South American sea lions may have influence on the fish population due to their diet. They are also important as prey for their natural predators (pumas, sharks, killer whales).