Steller sea lion
The Steller sea lion is the largest member of the eared seal family, known for its impressive size and distinctive characteristics. Found in the North Pacific Ocean along the coasts of California, Alaska, Russia, and Japan, these marine mammals feature a blunt snout and sparse underfur, with adult males showcasing thick manes. They typically weigh between 500 and 2,400 pounds and can reach lengths of up to 11 feet. Steller sea lions are carnivorous, feeding on a diverse diet that includes fish, squid, and crustaceans, while facing threats from predators like killer whales and large sharks.
Breeding occurs on specific islands, predominantly from mid-May to July, with a gestation period of one year resulting in the birth of a single pup. The weaning process can extend up to two years, which is notably the longest among eared seals. Steller sea lions have a lifespan of 20 to 30 years, but they are currently classified as an endangered species due to factors such as hunting, commercial fishing, climate change, and pollution. Their unique adaptations to both aquatic and terrestrial environments highlight their importance within the marine ecosystem.
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Steller sea lion
The steller sea lion is the largest of the eared seals, and sometimes even eats the pups of other kinds of eared seals, like the Northern fur seal. Stellar sea lions can be found in the North Pacific Ocean off the coasts of California, Alaska, Russia, and Japan.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Otariidae
Genus: Eumetopias
Species: Jubatus
Steller sea lions have blunt snouts and sparse underfur. Baby sea lions are dark brown to blackish. An adult has a light to reddish brown coat. Adult males have heavy manes, and they can weigh over 2,500 pounds (around one metric ton). Average weights for stellar sea lions range from 500 to 2,400 pounds (227 to 1134 kilograms). Stellar sea lions measure 7 1/2 to 11 feet (two to 3 1/3 meters) long. Sea lions use their foreflippers to push themselves quickly through the water, and they are also very agile on land. Steller sea lions are called lions because of the thick manes on the males and the way they roar like lions.
To preserve heat in the near-freezing water where they live, the steller sea lions have a smaller surface area with few appendages, such as fingers or toes. They also have a thick layer of fatty tissue, called blubber, beneath the skin.
Sea lions eat and travel in the water, and breed on land. They are carnivores, or meat-eaters. Their diet consists of a wide variety of fish, squid, octopus, bivalve mollusks, shrimps, and crabs. Predators include killer whales, large sharks, and humans.
The breeding islands for sea lions include the Kuril Islands, Kamchatka, the Aleutian Islands, and along the Alaskan-Canadian coastline. In the summer months, typically between mid-May and July, the bulls, or adult males, and their mates, or cows, will climb up on one of these islands and begin breeding. The gestation period (duration of pregnancy) is one year. The cows will then give birth to their one pups. A week later the males will mate again with cows that are also ready to mate. Shortly after mating, the females will go back to sea to feed. The males stay with the pups for the entire breeding season. The bulls will not leave the island, not even to eat, so they get much thinner during these months. The mothers return periodically to nurse the pups. Weaning can go on for up to two years for the steller sea lion, the longest weaning period for eared seals. Males and females are ready to mate when they are between three and six years old.
Steller sea lions have a natural life span of 20 to 30 years. Hunting, commerical fishing, climate change, and pollution have made the stellar sea lion an endangered species.
Bibliography
Keranen, Danielle. “ADW: Eumetopias Jubatus: Information.” Animal Diversity Web, 2013, animaldiversity.org/accounts/Eumetopias‗jubatus. Accessed 23 Apr. 2024.
“Steller Sea Lion - Facts, Diet, Habitat, & Pictures on Animalia.bio.” Animalia, 2024, animalia.bio/steller-sea-lion. Accessed 23 Apr. 2024.