UCLA

The United States Marine Mammal Protection Act (MMPA 1972) resulted in federal protection and enhanced the recovery of California sea lion (CSL--Zalophus californianus) populations in the United States. As an unintended consequence of their protection, sea lion populations have expanded their range, negatively interacting with every commercial fishery on the west coast of the United States, predating endangered Pacific salmonids at upriver dams, and damaging docks/fishing vessels. Conservation and management problems with California sea lions can benefit from mechanistic insights into how individuals respond to stimuli and learn about biologically important events. This dissertation provides an in depth examination into how animal learning theory can be applied to conservation issues. I apply learning mechanisms to enhance management of two conservation issues involving sea lions; depredation (removal of fish from fishing lines) and predation of endangered salmonids at the fish ladders below the Bonneville Dam. This dissertation is structured into two reviews, an empirical test of learning on deterrents on California sea lions (Zalophus californianus) interacting with fisheries, an analysis of social transmission and the impact of culling of California sea lions foraging at the Bonneville Dam. Chapter two unpacks the behavioral mechanisms involved in non-lethal deterrents and reviews their application for depredating marine mammals. This review makes the argument that Pavlovian fear conditioning can applied to deterrents to enhance success in cases of human wildlife conflict and reduce management concerns over non-target animals. Chapter three presents a field experiment on Pavlovian fear conditioning for deterrents on wild California sea lions which examines whether conditioned individuals exhibit greater avoidance compared to control animals. Chapter four reviews how learning can be applied to solve conservation problems. Social learning, for instance, functions as a multiplier, rapidly spreading undesirable wildlife behaviors through populations, suggesting that target lethal or non-lethal management strategies may be necessary. Chapter five uses social network based diffusion analysis to show that social transmission is driving foraging of endangered salmonids by California sea lions. Social transmission has implications for management measures, and we used epidemiological models of behavioral transmission to assess current and potential lethal removal strategies.