Individual identity is communicated through multiple pathways in male rock hyrax (Procavia capensis) songs

Communicating individual identity is essential for stable social systems. It is assumed that there are benefits for both senders and receivers to provide and discriminate identity cues. In this study, we investigate the possible routes senders use to acoustically broadcast their individual identity. Using discriminant function analysis of temporal and spectral acoustic measurements and analysis of song-element order, we explore the means male rock hyrax (Procavia capensis) singers utilize vocalization to express individual identity. Despite the fact that males use only three song elements, the pattern of acoustic characteristics, their temporal and frequency attributes vary according to the identity of singer. We show that in hyrax, individuality is expressed by highly variable, complex signals that are not condition dependent and are stable over years in singers that did not alter their spatial position. We also show that individuality signals are not linked to relatedness or to geographic location. The ability to discriminate individuals from vocal signatures needs to be further tested using controlled playback experiments.