Overview: Expanding an animal's self-world to include conspecifics.

To further the thinking about animal communication, the authors have returned to J. von Uexküll's (1934/1957) original writings on the Umwelt. Applying J. von Uexküll's self-world concept to studies of communication helps to highlight some of the unanswered questions in behavior. The authors illustrate that some researchers have adopted views that complement and expand the ideas outlined in J. von Uexküll's classic concept of an Umwelt by exploring the influence of individual, social, and ontogenetic contexts on communication. The authors maintain that further application of these concepts expands the understanding of animal communication and, more generally, of animal behavior.