Interesting Creatures... South American sea lion (Otaria flavescens)

Interesting Creatures… South American sea lion (Otaria flavescens)

Feb 16, 2020 Interesting Creatures in Guyana, News

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 Ecuadorian, Peruvian, Chilean, Falkland Islands, Argentinean, Uruguayan, and Southern Brazilian coasts. It is the only member of the genus Otaria.
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. 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). This species is even more sexually dimorphic than the other sea lions.
The South American sea lion is found along the coasts and offshore islands of South America, from Peru south to Chile in the Pacific and then north to southern Brazil in the Atlantic. 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. However, the movement ecology of South American sea lions remains poorly understood, although biologging studies in recent years have advanced the understanding of their at-sea movements at some breeding locations.
South American sea lions breed on beaches made of sand, gravel, rocky, or pebble. They can also be seen on flat, rocky cliffs with tidepools. Sea lion colonies tend to be small and scattered, especially on rocky beaches. The colonies make spaces between each individual when the weather is warm and sunny. They can also be found in marinas and wharves, but do not breed there.
South American sea lions consume numerous species of fishes, 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 may forage at the ocean floor for slow-moving prey or hunt schooling prey in groups, depending on the area. 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 killer whales and sharks, and visited as a handy source of blood by common vampire bats.
Mating occurs between August and December, and the pups are born between December and February. Males arrive first to establish and defend territories, but then switch to defending females when they arrive. A male aggressively herds females in his territory and defends from both neighbours and intruders.
During the breeding season, males that fail to secure territories and harems, most often subadults, will cause group raids in an attempt to change the status quo and gain access to the females. Group raids are more common on sandy beaches than rocky ones. These raids cause chaos in the breeding harems, often splitting mothers from their young. The resident males try to fight off the raiders and keep all the females in their territorial boundaries.
Raiders are often unsuccessful in securing a female, but some are able to capture some females or even stay in the breeding area with one or more females. Sometimes, an invading male abducts pups, possibly as an attempt to control the females. They also take pups as substitutes for mature females.
Subadults herd their captured pups and prevent them from escaping, much like adult males do to females. A pup may be mounted by its abductor, but intromission does not occur. While abducting pups does not give males immediate reproductive benefits, these males may gain experience in controlling females. Pups are sometimes severely injured or killed during abductions.
Despite being mostly a harem-territorial species, one population in Peru has been recorded having a lek-like breeding system. Here, with its longer ratio of males in comparison to females, the males cluster together and display and try to attract females while allowing them to move freely. The warmer climate also makes the females move constantly to the water, further making the traditional mating system difficult to maintain.
Sea lion mothers remain with their newborn pups for nearly a week before making a routine of taking three-day foraging trips and coming back to nurse the pups. They act aggressively to other females that come close to their pups, as well as alien pups that try to get milk from them. Pups first enter the water at about four weeks and are weaned at about 12 months. This is normally when the mother gives birth to a new pup. Pups gradually spend more time in the nearshore surf and develop swimming skills.
[Source: Wikipedia]