Understanding mate choice signal-receiver dynamics using a phase space embedding approach

Animal signals are selected to 1) maximize detection and 2) increase the likelihood of eliciting a response. While previous work has investigated visual and acoustic signals, postural movements represent a distinct and largely understudied signaling axis. Here we use high-resolution descriptions of animal movement to build a principled basis for investigating courtship signaling dynamics in guppies. We show that males and females occupy distinct behavioral subspaces. And during courtship these differences are further exaggerated as males produce stereotyped displays at the extremes of the behavioral space. States where behavioral trajectories become unstable, and are more likely to switch are disproportionately used both preceding (by males) and following courtship (by females). Coordination between males and females peaks immediately before courtship, and after courtship males show increased behavioral influence on females. Together, this provides the first quantitative evidence of signal maximization and receiver response dynamics in postural signaling interactions which are key predictions provided by signaling theory in animal communication, and exemplifies how quantitative, data-driven descriptions of system behavior may be used to directly inform ethological theory.