Chimpanzees show the capacity to communicate about concomitant daily life events
One universal of human language is its versatility in communicating about juxtapositions of everyday events. Versatile combinatorial systems of communication can be selected for if (a) several vocal units are flexibly combined into numerous and long vocal sequences and (b) vocal sequences relate to numerous daily life events. Chimpanzees fulfil (a) but there is limited evidence for (b) in non-human animals. We propose (b) is more likely during simultaneous or serial (concomitant) events than single events. We analysed 9391 vocal utterances across the repertoire of wild chimpanzees and their events of production. Chimpanzees used vocal sequences across a range of daily life events and twice as often during concomitant than single events. Also, utterance diversity correlated positively with event diversity. Our results show the potential of chimpanzee vocal sequences to convey combined information about numerous daily life events, a step from which generalised combinatoriality could have evolved.