California sea lions are the best-known eared seals. All seals can hear, but earless seals (in the family Phocidae) have internal ears. The eared seals (sea lions and fur seals, in the family Otariidae) have small external ears. They also can pull their rear flippers up under their bodies and use to them move around on land, which phocids cannot do. California sea lions spend most of their time in coastal waters, and eat fish. Adult males migrate northward for the winter and return to island beaches off the California and Mexican coastlines for the May—July breeding season. They loudly defend patches of territory, on land or in the shallows, fasting for 4—6 weeks while they are on patrol. About a month after pupping (giving birth), females are ready to mate with the males who have been waiting impatiently. Ninety percent of the young are born in June. They are born on land and nurse for a year or more.

Links:
Mammal Species of the World