Advances in the Study of Behavior was initiated over 40 years ago to serve the increasing number of scientists engaged in the study of animal behavior. That number is still expanding. This volume makes another important "contribution to the development of the field" by presenting theoretical ideas and research to those studying animal behavior and to their colleagues in neighboring fields. This volume reflects many of the current themes in animal behavior including the evolution of social behavior, sexual selection and communication. It also reflects controversial topics on which the authors provide interesting, new insights. Advances in the Study of Behavior is now available online at ScienceDirect ― full-text online from volume 30 onwards.