To establish a framework for discussing mammalian vocalizations, relevant terminology and concepts from the theory of nonlinear dynamics are introduced. It is suggested that a variety of nonlinear phenomena including subharmonics, biphonation, and deterministic chaos are normally occurring phonatory events. The whole spectrum of these phenomena can be found in the repertoire of the African wild dogLycaon pictus.In addition, examples of nonlinear phenomena in a wide range of other mammalian taxa will be presented. Moreover, some artifacts in sound spectrographic analysis are listed which may be misinterpreted as nonlinear phenomena.