Nonlethal Effects in the Ecology of Predator-Prey Interactions

.P ]redator-prey interactions have long captured the attention of ecologists, and with good reason. Predation leads inevitably to the removal of prey individuals from ecological systems, which can have major impacts on prey population dynamics and on entire ecosystems. Interest in predator-prey interactions can be traced to the foundations of modern ecology, from early work on predator-prey population dynamics by historical figures such as Lotka, Volterra, and Gause (Taylor 1984) to classic work on the role of predation in regulating species diversity (e.g., Paine 1966). Ecologists continue to be greatly interested in predation and its effects on populations, communities, and ecosystems (Crawley 1992, Carpenter and Kitchell 1993). A perusal of any recent textbook on ecology will not only confirm the importance of predation in modern ecology, but also illustrate the preeminence of the perspective on predation-that is, predation is seen as important only insofar as it results in the death of prey and their removal from the system. However, the obvious and sometimes dramatic lethal aspects of predation can obscure the nonlethal effects of the mere presence of predators in an ecological system. In the presence of predators, prey may alter their behavior so that they are more difficult