In order to study the evolution of language, it is useful to understand the communicative systems of nonhuman animals. To this end, descriptive ethograms of primate vocal repertoires are the ideal starting point. We examined the vocal repertoire of a group of captive Guinea baboons (Papio papio). Twelve vocalizations were readily distinguishable using individual call components and call sequences. Some of these vocalizations were sex and/or age specific (e.g., copulation grunts in females, moans in infants). We compared these vocalizations to those reported in wild Guinea baboons as well as the other baboon taxa. The Guinea baboons share the basic call units with the other baboon species. However, a large degree of variability occurs within call sequences (e.g. number of grunts within a bout, F0 and calling rate [number of grunts/second]). The baboons also showed vocal variability through the combination of different vocalizations (e.g. moans, screams and yaks in varying order and number within a bout) and the use of one vocalization (barks) in a new captive-specific context. The present study complements...