Advances in the Study of Behavior continues to serve scientists across a wide spectrum of disciplines. Focusing on new theories and research developments with respect to behavioral ecology, evolutionary biology, and comparative psychology, these volumes serve to foster cooperation and communication in these diverse fields. Volume 23 focuses on research on the lower vertebrates with respect to the functional significance of different breeding strategies, the level at which natural selection acts, methods of teasing apart the genetic control of behavior, the assumptions underlying models of territoriality, and signalling systems and the sensory mechanisms on which they depend.