How animals produce rhythm – an overview of ethological mechanisms for rhythmic communication

Animals communicate with a staggering diversity of rhythmic signals, yet behind all this diversity lies a small number of ethological mechanisms. In this chapter, we provide a quick review of how animal produce rhythmic signals based on these mechanisms, which span tremulation, percussion, bodily displays, stridulation, tymbalation, aerodynamic sound production (including vocalisation), as well as the production of luminescent, chromogenic and electric rhythms. We point out that these ethological mechanisms which underlie the production of communicative rhythms appear to be derived from rhythmic praxic behaviours that initially evolved to implement vital functions such as breathing, feeding, locomotion, defense or procreation. Based on the findings reviewed by the chapter, we identify three important areas for future research for advancing our understanding of the evolution of rhythmic communication. First, there is a massive research gap when it comes to quantifying how rhythmic signals unfold and interact across perceptual and behavioural modalities. Second, there is a need to understand how behavioural rhythms relate to — and are constrained by — their underlying neuromuscular substrates. Third, very little is known about the relationship between communicative rhythms and the praxic behaviours in which they putatively originated.