Sea lions are marine mammals of the eared seal family. They have long, tapering bodies covered with thin, short, coarse hair. Their limbs are modified into flippers that are larger than those of true seals. Also unlike true seals, sea lions have small external ears and can turn their hind flippers forward to move about on land. The California sea lion is one of four major types. It inhabits the west coast of North America and the Galapagos Islands. All of the species have highly developed social systems. They gather on shore during the breeding season. The males, which are several times larger than the females, vie for harems which can number up to 15 females. Sea lions principally feed on fish and squid. They are capable of diving up to 600 feet (180 m) for food.