text: information and pictures of sea lions? a biography family and species - the variety of sea lions which live at sea lion caves is commonly called the northern, or steller, sea lion. this sea lion is named after george wilhelm steller, an eminent german naturalist who accompanied the russian explorer vitus bering in 1741 on his second alaskan expedition. steller was the first qualified observer to study and classify these animals. the steller sea lion is a member of the otariidae family, or eared seal. it is characterized by an external ear which can be closed when entering water and by hind feet or flippers that point forward. in contrast, phocidae, or true seal, has no external ears and it's rear flippers point backward. also belonging to the otariidae family is the california sea lion and the alaska fur seal. the alaska fur seal (callorhinus alascanus), is not found at sea lion caves. the california sea lion (zalophus californianus) is seen all along the pacific coast and is generally found at sea lion caves from late fall to early spring. it readily adapts to captivity and is trained for circus acts. the largest of the eared seal family and the principal tenant of sea lion caves is the steller sea lion. this animal is also considered non-migratory because there is no mass movement to summer or winter grounds, although individuals or small groups may travel hundreds of miles in search of food. it is found from the central california coast, north to the bering sea and back south into northern japanese waters. a recent u.s. fish and wildlife survey indicates a possible total population of nearly 80,000 steller sea lions. most of these animals live on the offshore islands and rocks of british columbia and alaska. some stellers live along the california coast and about one thousand reside in oregon waters. the number of steller sea lions in the sea lion caves area varies from season to season and from year to year with the herd averaging about 200 animals.  physical characteristics - sea lions are mammals, or warm blooded animals which give birth, nurse their offspring, and must breathe air. sea lions are also pinnipeds -- literally, feather-footed -- meaning they have finlike members for propulsion. their pelvic bone structure allows independent use of their flippers, and therefore, they can walk on their four weblike flippers which contain the same bony structure as the legs of land animals. in the water, the steller sea lion swims by using a breast stroke and may reach a top speed of about 17 m.p.h. in contrast, other marine animals, such as the whale, depend on fishlike body action to move through the water. the true fur seal folds its front flippers and swims by the force of its trailing rear flippers. young sea lions called pups seem to be immune to most diseases as long as they are breast fed. as they mature, pups become susceptible to internal parasites such as round worms and tape worms which are a deterrent to both growth and longevity. population increases are also somewhat checked by adult sea lions inadvertently trampling their young and also by accidental drownings of the newly born which have not yet learned to swim. diet - sea lions are carnivorous. their skulls are similar to those of bears and their jaws contain sharp teeth much like those found in dogs, cats, and other flesh eaters. they feed exclusively on fish they catch themselves; their diet varying with whatever is abundant in the area. in the vicinity of sea lion caves, they appear to subsist chiefly on bottom fish such as skate, small sharks, squid and various species of rock fish. sea lions may descend in search of food to a depth of 80 to 100 fathoms, and normally remain submerged no longer then four or five minutes. possible sea lion predation on commercially valuable fish has been of some concern. because of the animal's remote and rugged habitat, and because collecting specimens at sea is difficult, much is unknown about its diet habits. however, recent scientific studies indicate th