A harem of California Sea Lions (Zalophus californianus) lay on the 'Monica One' at the Santa Monica Pier on Friday, May 22, 2009. Sea Lionsare quite intelligent, can adapt to man-made environments, and can be easily trained. Because of this, California sea lions are commonly used for entertainment in circuses, zoos and marine parks; and are used by the US Navy for certain military operations.They can be trained to do different behaviors such as throwing and catching balls on their noses, running up ladders, or honking horns in a musical fashion.California sea lions grows to 660 lb and 8 ft long, while females are significantly smaller, at 210 lb and 6.5 ft long.