Matching vocalizations to faces of familiar conspecifics in grey-cheeked mangabeys (Lophocebus albigena).

Integration of information coming from several sensory modalities is crucial for communication and individual recognition in many species. In this experiment, we tested 6 grey-cheeked mangabeys with still pictures and vocalizations of familiar conspecifics. During the tests, the subjects faced 2 computer screens. Pictures of different familiar conspecifics were displayed simultaneously on each screen, and the vocalizations of 1 of the 2 individuals were played. We recorded the subjects' fixation time towards each computer. Fixation time towards the individual whose vocalization was played was different from chance in most cases, which seems to be an indication of the mangabeys' abilities to match faces of known conspecifics to their vocalizations. However, we found differences according to the kind of vocalization, the subject tested and the identity of the conspecific presented.