"This book describes basic theory about how bird communication works: 1) how signals should evolve to be optimally functional in the environment, 2) how senders use signals to transmit information, 3) how receivers perceive the information content of a signal, and 4) why we should expect signals to evolve to give honest, reliable information to receivers about senders. It describes channels of communication (plumage & sounds), how signals are produced and perceived by birds, and their topics of communication"--