~ Sea Lions ~
General Info: Sea lions are pinnipeds characterized by external ear flaps, long foreflippers, the ability to walk on all fours, and short, thick hair. Together with the fur seals, they comprise the family Otariidae, eared seals and there are six extant and one extinct species (the Japanese Sea Lion) in five genera. Their range extends from the subarctic to tropical waters of the global ocean in both the Northern and Southern Hemispheres. They have an average life span of 20–30 years. A male California sea lion weighs on an average about 600 pounds and is about 8 feet long, while the female sea lion weighs an average 200 pounds and is approximately 6 feet long. The largest sea lion is the Steller's Sea Lion which can weigh slightly over 2000 pounds and grow to a length of 10 feet. Sea lions consume large quantities of food at a time and are known to eat about 5–8% of their body weight at a single feeding.
Family: Together with the fur seals, sea lions constitute the Otariidae family, collectively known as eared seals. Until recently, sea lions were grouped under a single subfamily called Otariinae, whereas fur seals were grouped in the subfamily Arcocephalinae. This division was based on the most prominent common feature shared by the fur seals and absent in the sea lions, namely the dense underfur characteristic of the latter. Recent genetic evidence, however, strongly suggests Callorhinus, the genus of the northern fur seal, is more closely related to some sea lion species than to the other fur seal genus, Arctocephalus. Therefore, the fur seal/sea lion subfamily distinction has been eliminated from many taxonomies. Sea lions are related to the walrus and the seal. Nonetheless, all fur seals have certain features in common: the fur, generally smaller sizes, farther and longer foraging trips, smaller and more abundant prey items and greater sexual dimorphism. All sea lions have certain features in common, in particular their coarse, short fur, greater bulk and larger prey than fur seals. For these reasons, the distinction remains useful.
Specific Differences Between Sea Lions and Seals: Both seals and sea lions, together with the walrus, are pinnipeds, which means "fin footed" in Latin. But seals' furry, generally stubby front feet (thinly webbed flippers, actually, with a claw on each small toe) seem petite in comparison to the mostly skin-covered, elongated fore flippers that sea lions possess. The next difference is that sea lions have small flaps for outer ears. The "earless" or "true" seals lack external ears altogether. You have to get very close to see the tiny holes on the sides of a seal’s sleek head. Sea lions are noisy. Seals are quieter, vocalizing by soft grunts. While both species spend time both in and out of the water, seals are better adapted to live in the water than on land. Though their bodies can appear chubby, seals are generally smaller and more aquadynamic than sea lions. At the same time, their hind flippers angle backward and don't rotate. This makes them fast in the water but basic belly crawlers on land. Sea lions, on the other hand, are able to "walk" on land by rotating their hind flippers forward and underneath their big bodies. This is why they are more likely to be employed in aquaria and marine shows. Lastly, seals are less social than their sea-lion cousins. They spend more time in the water than sea lions do and often lead solitary lives in the wild, coming ashore together only once a year to meet and mate. Sea lions are so social that they congregate in gregarious groups called herds or rafts that can reach upwards of 1,500 individuals!
History with Humans: Some species of sea lion are readily trainable and are often a popular attraction at zoos and aquariums. They typically have performing behaviors such as throwing and catching balls on their noses and clapping. The U.S. Navy's Marine Mammal Program, based in San Diego, has trained sea lions to detain scuba divers.
The Moche people of ancient Peru worshipped the sea and its animals. They often depicted sea lions in their art. Sea lion attacks on humans are rare. In a highly unusual attack in 2007 in Western Australia, a sea lion jumped from the water and seriously mauled a 13-year-old girl surfing behind a speedboat. The sea lion appeared to be preparing for a second attack when the girl was rescued. An Australian marine biologist speculated the sea lion may have viewed the girl "like a rag doll toy" to be played with.
In San Francisco, where an increasingly large population of California sea lion crowd docks along San Francisco Bay, there have been incidents in recent years of swimmers being bitten on the legs by large, aggressive males, possibly as territorial reasons.
Sea lions have also been reported to assist or save humans who show signs of distress in the open waters. In June 2000, Kevin Hines leaped into San Francisco Bay; he reportedly was saved by a sea lion that kept him afloat until help arrived.
Threats to the Species: The greatest threat to the species at this time is the demands on their main food source, fish. Over fishing is causing terrible problems with sea lions finding enough food. Spring 2013 has been particularly hard on sea lions where numerous pups have been rescued being found stranded on beaches starving because there is such a lack of food for them in their natural habitat. To learn more about this event read the NOAA Fisheries announcement titled "2013 California Sea Lion Unusual Mortality Event in California".