Bioacoustic cues and their relations to dominance rank in Père David’s deer stags

The vocal display of male animals during the breeding season has received particular attention. To find out whether male acoustic signals could be a quality-assessment cue of callers, we conducted a study on Pere David's deer (Elaphurus davidianus) characterised by a polygynous mating system and high male-male competition during the rutting season. We investigated the relationship between the stag's acoustic properties and the dominance rank as an indication of quality. Results showed that (1) there were two types of calls, the common roar and the chasing bark, (2) there was no significant difference between the call duration of the common roar and the chasing bark among different dominance ranks, (3) in the common roar, the value of the fundamental frequency, formant frequencies and formant spacing decreased significantly with the rise of dominance ranks and (4) vocal intensity of the common roar differed significantly among the three dominance ranks such as the harem master, the challengers and the bachelors. Our results suggested that some acoustic features, such as formant frequencies, formant spacing and vocal intensity of the common roar were closely related to the dominance rank and could be effective indicators of male competitive ability.