The average lifespan of Southern American sea lions is 16 to 20 years. One captive sea lion, at the Valley Zoo, in Edmonton, Canada, is 30 years old (in 2008).
Range lifespan
Status: captivity: 30 (high) years.
Typical lifespan
Status: wild: 16 to 20 years.
Average lifespan
Status: captivity: 24.8 years.
Their predators include pumas, sharks, and killer whales.
Known Predators:
South American sea lions (Otaria flavescens), also known as maned seals, are the most sexually dimorphic of the five known sea lion species. Males are approximately three times the size of females.
Adult males range from 2 to 2.5 meters in height and can weigh from 200 to 350 kilograms. The coat is dark brown on the dorsal side and dark yellow to gold on the ventral side. Males have a full mane, which is a paler color than the coat and a larger, more muscled neck than do females. A male's posture is usually upright, with the rostrum turned upward.
Adult females are much smaller in size and weight. They average 2 meters in height and can weigh from 140 to 150 kilograms, roughly half the average weight of an adult male. Their coats are also lighter in color relative to males. Coat color ranges from a fair brown to yellow with some pale markings around the head.
Pups do not exhibit this brown color until about a month after they are born. Neonates are greyish orange ventrally and black dorsally. This coat later turns to a dark chocolate brown color. Sexual dimorphism is shown in pups as well as in adults. According to a study in Peninsula Valdes, Argentina (Capposso et. al 1991), male pups averaged .82 meters in length and 13.7 kilograms in weight. In contrast, female pups averaged .79 meters in length and 12.3 kilograms in weight
Range mass: 140 to 350 kg.
Range length: 2 to 2.5 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; ornamentation
South American sea lions reside along shorelines and beaches. These beaches usually consist of sand, gravel, rocks, and/or pebbles. They also inhabit flat rocky shelves or cliffs with tidepools and boulders.
Habitat Regions: temperate ; terrestrial ; saltwater or marine
Aquatic Biomes: coastal
Other Habitat Features: intertidal or littoral
Otaria flavescens inhabits South American coastlines from Rio de Janeiro (23 degrees south latitude) on the Atlantic ocean side and coastal Perú (5 degrees south latitude) on the Pacific coast to southernmost South America. There are records of Otaria flavescens inhabiting the Galapagos and Falkland Islands.
Biogeographic Regions: neotropical (Native ); atlantic ocean (Native ); pacific ocean (Native )
South American sea lions are carnivorous. They feed on fish, cephalopods, crustaceans, and other invertebrates depending on local abundance. These sea lions are typically found hunting in shallower waters, not more than five miles from shore. When looking for prey that travel in schools they hunt in groups. When they catch fish, they usually shake the prey in the air and then sometimes eat it whole. In addition, they have been observed eating penguins and female South American fur seals (Arctocephalus australis) and their pups.
Animal Foods: birds; mammals; fish; mollusks; aquatic crustaceans
Primary Diet: carnivore (Piscivore )
Until recently Otaria flavescens was hunted for its fur, meat, and oil.
South American sea lions will steal fish from human fishing grounds by following fishing boats and stealing fish from the nets.
Negative Impacts: crop pest
South American sea lions are not presently threatened. They experienced a large population decline during the past 70 years in the Falkland Islands. The reason for this abrupt decline is unknown.
Though they are not currently threatened, they are protected throughout most of their range.
The IUCN rates the species at "Lower Risk."
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Perception Channels: tactile ; chemical
Otaria flavescens was previously known by the name Otaria byronia.
The ancestors of Southern American sea lions are from the Oligocene and Miocene era, about 25 million years ago. Enaliarctids are hypothesized to be the ancestors of these eared seals.
Otaria flavescens is known for its polygynous lifestyle. Mating season occurs from early August to December, when males defend territories aggressively and show interest in females. Mating behavior includes mutual vocalizations, snout and mouth contact, smelling, and playful biting. Territories for breeding grounds are usually on beaches of sand, pebbles, or flat rock. Males prevent females from leaving the beaches until they have mated.
Mating System: polygynous
Birth occurs from mid-December to early February in the year after mating, with the bulk of births during mid-January. The gestation period is about 11.75 months. There is typically one pup per birth, which averages .80 to .85 meters in length and 10 to 15 kilograms in weight. Male pups tend to be larger than females. However, since mothers seem to not show any gender-based nursing difference, the gender bias in parental investment occurs only during gestation. The heightened maternal investment in male offspring is important for their reproductive success, as size is important to males in establishing their mating territories.
Mothers fast for 5 to 7 days after giving birth in order to nurse their pup. Soon after giving birth mothers enter oestrus and mate again with the male in whose territory they have given birth. After mating, the mother leaves her pup behind to find food in the sea.
Since individuals mate and breed synchronously with hundreds of other sea lions, pups are protected from both predators and abduction when the mother is away, as they are not left "alone" on the beach. The simultaneous birthing system also promotes group bonding among pups.
There are some negative consequences to mass birthing also. It triggers the mother's aggression level toward other female sea lions in defense for her pup. Mothers return from their feeding trips in intervals to nurse their young. A female is able to locate her pup by first calling to it and finally identifying it by smell.
Sometimes a mother is separated from her pup and is not successful in finding it. This occurs as a result of several factors such as high tide, storms, male abductions, and inexperience of a young mother.
Pup mortality can range from 2 to 50%, depending on the size of the population. Larger populations experience higher pup mortality because of the greater risk of pups being trampled to death by adult sea lions. Pup mortality can be due to predators (such as pumas), diseases, parasites, drowning, subadult males, and starvation (when they lose their mothers).
Pups spend most of their time in groups or pods playing, sleeping, or residing near the water. They rarely swim into the deeper waters unless accompanied by their mothers. They typically first enter the water at about 3 to 4 weeks of age with other sea lions in a large group. They continue to nurse for about 6 to 12 months, until the mother gives birth to another pup. Even then, mothers have been known to nurse both pups simultaneously.
Male pups mature later than female pups. Male pups reach maturity at 6 years of age, whereas females mature at 4 years of age. Both sexes reach their full adult size around 8 years of age.
During development, mothers must be aware of group raids by invading males, who abduct their pups. These raids can take place at any time of the day or night but are correlated with the number of females in oestrus, their location, and the tide level. Raiding and abudction of pups may be timed to occur early during the female's oestrus, in order to attract mothers away from their terrritory for mating purposes. These raids may also signify strength and power. Some pups are killed by the males during raids. Mothers do not usually leave grounds and try to retrieve a pup if it is abducted. The mother is helpless in fighting the male because of his much larger size. Some researchers have suggested that males abduct pups to gain practice in controlling females during the mating season.
Breeding interval: These animals breed annually.
Breeding season: Mating occurs from August through February, at the time when pups are born and females return to estrus.
Average number of offspring: 1.
Range weaning age: 12 (high) months.
Range age at sexual or reproductive maturity (female): 3 to 4 years.
Range age at sexual or reproductive maturity (male): 6 (high) years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous
Average birth mass: 12500 g.
Average gestation period: 357 days.
Average number of offspring: 1.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female)
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 western and southeastern coasts of South America. It is the only member of the genus Otaria. The species is highly sexually dimorphic. Males have a large head and prominent mane. They mainly feed on fish and cephalopods and haul out on sand, gravel, rocky, or pebble beaches. In most populations, breeding males are both territorial and harem holding; they establish territories first and then try to herd females into them. The overall population of the species is considered stable, estimated at 265,000 animals.
The South American sea lion was classified as Otaria flavescens by George Shaw in 1800 and as Otaria byronia by Henri Marie Ducrotay de Blainville in 1820. The two nomenclatures were historically used interchangeably, but O. flavescens has become the preferred name.[3][4] The species is also known by the common name "southern sea lion", although it is not preferred since the Australian sea lion and New Zealand sea lion also range in the Southern Hemisphere. Locally, it is known by several names, including león marino (sea lion) and lobo marino (sea wolf).[3]
The South American sea lion is among the largest of and most sexually dimorphic of the eared seals. Males measure up to 3 m (9.8 ft) in length with a weight of 350 kg (770 lb) while females reach a length 2 m (6 ft 7 in) and reach 150 kg (330 lb) in weight. Pups are born 0.86 m (2 ft 10 in) long and weigh 12–15 kg (26–33 lb). Size differences between the sexes exists in both newborns and juveniles.[3]
Adult males have large heads with short, upturned snouts and long manes which reach the shoulders.[5] The fur is mainly brownish with adult males being dark brown and females being nearly yellowish. Pups are born black but become reddish-brown after their first molt.[3]
The South American sea lion is found along the coasts and offshore islands of South America, from Peru south to Cape Horn and then north to southern Brazil.[5][3] 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.[5] However, the movement ecology of South American sea lions remains poorly understood, although biologging studies in recent years have advanced our understanding of their at-sea movements at some breeding locations.[6][7][8][9] There is no evidence of a winter migration of sea lions from the Falkland Islands.[10]
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.[5]
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.[5] They have even been observed preying on penguins, pelicans, and young South American fur seals.[11] 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.[5] South American sea lions have been recorded to take advantage of the hunting efforts of dusky dolphins.[12] The sea lions themselves are preyed on by orcas and sharks; at Peninsula Valdes, orcas will beach themselves and grab sea lions near shore.[3]
Mating occurs between December and February. Males arrive first to establish and defend territories, but then switch to defending females when they arrive. Estrus in females usually begins 6 days after the birth of a pup and soon after the copulations start with a peak in January. A male aggressively herds females in his territory and defends from both neighbors and intruders. On rocky beaches, males establish territories where females go to cool off, keeping them until estrous. On cobble or sandy beaches, males have territories near the surf and monopolize females trying to get access to the sea. The number of actual fights between males depends on the number of females in heat. The earlier a male arrives at the site, the longer his tenure will be and the more copulations he will achieve. Males are usually able to keep around three females in their harems, but some have as many as 18.[13][5]
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.[14][15]
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 then to move freely. The warmer climate also makes the females move constantly to the water, further making the traditional mating system difficult to maintain. The group raids that exist in temperate populations are virtually non-existent here.[16]
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.[13][5] They act aggressively to other females that come close to their pups, as well as alien pups that try to get milk from them.[17] 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.[5]
South American sea lions are observed to make various vocalizations and calls which differ between sexes and ages. Adult males make high-pitched calls during aggressive interactions, barks and growls when establishing territories, growls when interacting with females, and exhalations after antagonistic encounters. Females with pups make a mother primary call when interacting with their pups, and grunts during aggressive encounters with other females. Pups make pup primary calls. Some of those vocalizations and acoustic features may support individuality.[18]
The Moche people of ancient Peru worshipped the sea and its animals. They often depicted South American sea lions in their art.[19] Two statues of this species are the symbol of the city of Mar del Plata.[20]
Indigenous peoples of South America exploited this species for millennia and by Europeans around the 16th century.[21] The hunting has since gone down and the species is no longer threatened. The species is protected in most of its range. Numerous reserves and protected areas at rookeries and haul-out sites exist for the sea lions. Despite this, protection regulations are not effectively enforced in much of animals' range.[1]
The overall population of sea lions is considered stable; the estimate is 265,000 animals. They are declining in the Falkland Islands, and in Argentina Patagonia, but are increasing in Chile and Uruguay.[1] Many sea lions of the Peruvian population died in the 1997/1998 el Niño.[1][22] They still are killed due to their habits of stealing fish and damaging fishing nets.[1]
_(Peninsula_de_Valdes,_Jan_1984).jpg)
{{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) 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 western and southeastern coasts of South America. It is the only member of the genus Otaria. The species is highly sexually dimorphic. Males have a large head and prominent mane. They mainly feed on fish and cephalopods and haul out on sand, gravel, rocky, or pebble beaches. In most populations, breeding males are both territorial and harem holding; they establish territories first and then try to herd females into them. The overall population of the species is considered stable, estimated at 265,000 animals.
