Here, a new conceptual framework for looking at animal vocal communication is proposed. It describes animals as managers, attempting to get other animals to behave in ways beneficial to the managing animal, and as assessors, behaving in their own interest that may or not be in the interests of the manager. The authors contend that it is this interplay between management and assessment that results in the functioning and evolution of animal communication. It will be a landmark volume for all those interested in animal communication.