Sea lions are adapted for movement on land as well as in the water. Winglike front flippers have bone structure similar to that in our arms and hands. Swimming with these flippers propels the sea lion forward, while the hind flippers steer. Both sets of flippers enable a sea lion to walk on land. Male California sea lions establish breeding territories on the beach from May to July along the coasts of Southern California and Baja California.
Males bark incessantly when defending their established territories.
Pups are born with their eyes open and can vocalize. They appear to be able to swim at birth, although their movements are not well coordinated. Several days after the pup's birth, the mother leaves the pup in the crowded rookery as she searches for food in the ocean. When she returns, the mother emits a loud trumpeting vocalization, which elicits a bleating response from her pup. This exchange continues until mother and pup find each other.