Growth and reproductive costs of larval defence in the aposematic lepidopteran Pieris brassicae.
A recent review by Lind and Cresswell (2005) noted some important difficulties with quantifying the fitness consequences of antipredator behaviors. In this paper, we discuss the conceptual and analytical tools available to behavioral ecologists for approaching the question of adaptive value in the broader context of whole organism performance and total fitness. Because these tools already exist, we feel that determining the fitness consequences of antipredator behavior, or any behavior for that matter, is not intractable. Instead, it seems that both the challenge and the solution lie in linking the theoretical concepts of evolutionary biologists to the empirical data typically collected by behavioral ecologists. We hope that this paper will help forge this link as well as serve as a reminder that when grounded in natural history and an appropriate quantitative, conceptual framework, empirical studies can still provide detailed answers to the increasingly complex questions we ask.