Vocal performance reflects individual quality in male Great Himalayan leaf-nosed bats(Hipposideros armiger)

Signals containing parameter trade-offs are likely to be honest indicators of signaler quality because they are difficult to produce.Signals with a trill-rate/bandwidth trade-off have been described for many songbird species,one mouse,and one non-human primate species.However,there were no reports about whether there is a vocal performance trade-off in social calls of bats.This study investigated(1)a possible vocal performance trade-off in territorial calls of male Great Himalayan leaf-nosed bats,Hipposideros armiger,recorded from 9 locations in south China,and(2)the relationships between vocal performance(vocal deviation and consistency)and caller’s quality(body mass)to determine whether vocal performance honestly indicates a caller’s quality.Vocal deviation measures the deviation of a call relative to an extreme call and vocal consistency measures the spectral consistency across a string of syllables.Our results showed a significant negative correlation between syllable repetition rate and frequency bandwidth,suggesting a vocal performance trade-off similar to the one in songbirds.Further,there was a significant negative relationship between body mass and vocal deviation,but no significant correlation between body mass and vocal consistency.This study provides thefirst empirical evidence for a vocal performance trade-off of social calls in bats,and the potential for the level of performance to indicate caller quality.