Effects of El Niño 1983 on the Foraging Patterns of California Sea Lions (Zalophus californianus) near San Miguel Island, California

During the 1983 El Nino event, California sea lions (Zalophus californianus) and Galapagos fur seals (Arctocephalus galapagoensis) responded to the reduction in food availability by extending their foraging trips to sea and delivering less milk to their pups (Trillmich and Limberger 1985; Ono et al. 1987). These observed changes likely reflected a change in foraging tactics as animals attempted to compensate for a reduced food supply. The manner in which these foraging patterns were altered, however, still remains unclear.