Weighing up a ton, the sea lion is a marine mammal living along the coasts of the Indian Ocean and the Pacific. Close-up on an animal with a massive body that is also called sea lion.
Sea lion identity card
The sea lion belongs to the family of Otariidae and as such, is also called sea lion. In this family, we distinguish sea lions on the one hand and fur seals on the other (better known under the name ofsea bear). The northern sea lion or Steller sea lion (Eumetopias jubatus) is the largest of the otariids. The origin of sea lions dates back almost 25 million years. These animals are among the pinnipeds, an order of aquatic mammals whose members have transformed into fins, as opposed to fissipeds which are terrestrial carnivorous mammals.
Description of the sea lion
The sea lion has a massive body, fusiform and a broad chest. Its hind limbs can be folded up allowing it to navigate underwater and move on land fairly nimbly. Its round head adorned with external ears displays long vibrissae that help it to detect its prey. The coat of the sea lions varies according to the species: some are black, others brown or almost blonde in color. In the sea lion, the sexual dimorphism is very marked, the male is indeed revealed three to four times bigger than the female. Their size and weight range from 1.50 meters and 300 kilograms for female Australian and California sea lions, to 3 meters and 1 ton for male Steller sea lions.
Range of the sea lion
The distribution of this marine animal is very varied and covers different coastal regions of the ocean. Indian (New Zealand and Australia) and the ocean peaceful (from the United States, especially southern California, to the Galapagos Islands) where they live in colonies. Depending on the region of the world, we meet various species such as:
- The sea lion of California : west coast of the United States, Alaska, Canada, Mexico;
- The sea lion of Steller : North Pacific, between Russia and Japan and also in Alaska;
- The sea lion south american : two coasts of South America (Argentina and Chile);
- The sea lion Australian : islands in southwest Australia.
Sea lion diet
The marine mammal stays near the coasts where it feeds mainly on Pisces such as pollock, herring, capelin, mackerel, redfish, salmon and sturgeon. The sea lion also eats shrimps, molluscs and cephalopods like squid and octopus. Steller’s sea lion is also known to be a predator young fur or harbor seals.
Sea lion behavior
The sea lion is an animal gregarious which is not considered to be migratory. If a male can travel long distances to find a female, he does not stray far from his place of birth. Excellent swimmer thanks to its pectoral fins which help it to propel itself, the sea lion also knows how to move on land with ease. To feed, the mammal usually dives to 60 meters (rarely more than 140 m) and does not stay more than two minutes in apnea. To its view adapted to water, are added a good smell and a keen hearing. During the breeding season, the male constitutes aharem and ardently defends its territory by means of ritualized combat: grunts, roars, butts and bites.
Reproduction of the sea lion
During the mating season which begins in mid-May, the males settle on a rock and stay there until July. without eating or drinking. They will not return to sea for food until after thecouplingIn the sea lion, the embryo does not begin to develop until after it is implanted in the uterus, thus leading to a gestation about 50 weeks. Every 2 years, the female gives birth to a baby unique weighing 17 to 24 kg and measuring 1 meter. Breastfeeding can last for 1 year but the young sometimes stays close to its mother until the age of 3. Males and females will reach their sexual maturity between 3 and 6 years old but will not reproduce until around 9 years old.
Conservation status of the sea lion
The main ones predators of the sea lion are killer whales and sharks. Western sea lion populations have declined by 70-80% since the 1970s and are steadily declining. In question: the hunt commercial and traditional, their accidental capture in fishing nets, pollution (including hydrocarbons) and the decline of their usual prey following the overfishing. If the Japanese sea lion has recently faded away, other species are considered in danger by the International Union for the Conservation of Nature (IUCN) as the Galapagos sea lion, the southern sea lion or classified as “vulnerable” (northern fur seal, Guadalupe Island sea lion, New sea lion -Zeeland). The lifetime sea lion ranges from 18 to 25 years old.