Vocal individuality in a group of manatees (Trichechus manatus manatus) under human care

The West Indian manatee is a marine mammal endemic in Central America. In manatees, vocalisations are used for social and mother-offspring communication. However, it is not clear whether vocalisations can encode information about individual identity. We collected acoustic recordings from an ex-situ group housed at Acquario di Genova. For each vocalisation, we measured several vocal parameters in order to perform a stepwise cross-validated discriminant function analysis (DFA). Our results suggest that acoustic cues of individuality are encoded in their calls. The DFA also resulted in the selection of three acoustic parameters (f0 mean, f0 end, and call duration) that were particularly important for vocal individuality. We recommend additional studies, using playback experiments, to investigate acoustic recognition in this species.