Distress calls of nectarivorous bats (Glossophaga soricina) encode individual and species identity

David Hörmann, Marco Tschapka, Andreas Rose & Mirjam Knörnschild (2021). Distress calls of nectarivorous bats (Glossophaga soricina) encode individual and species identity. Bioacoustics, Volume 30 (3): 253 -271

Distress calls are known from a variety of animals and are defined as vocalisations emitted during extreme physical stress. Even though distress calls have been studied for a long time, their precise advantage for callers or the significance for receivers is still unclear. In this study, we describe distress calls of the nectarivorous bat Glossophaga soricina (Phyllostomidae: Glossophaginae). Analysing 1925 distress call syllables from 15 individuals caught in the field, we defined six different syllable types. Distress calls were high-intensity, broadband sounds with a low frequency range and thus comparable to those of other taxa. We found statistical evidence for an individual signature in distress calls, but not for a sex-specific signature. Further, playback experiments revealed that group-housed bats responded to distress calls, whereas single-housed bats did not, suggesting that the bats’ response behaviour is influenced by group size. Bats responded significantly to normal and distorted conspecific distress calls but not to heterospecific distress calls. We found no sex-specific differences in the response to different playback stimuli. In conclusion, our results indicate that distress calls of bats encode important social information that can be used by receivers and that the response behaviour of receivers depends on the presence of conspecifics.


Fear screams, group size, information content, playback experiment, response strength, syllable types