RT Journal Article SR Electronic T1 Titi monkeys combine alarm calls to create probabilistic meaning JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaav3991 DO 10.1126/sciadv.aav3991 VO 5 IS 5 A1 Berthet, Mélissa A1 Mesbahi, Geoffrey A1 Pajot, Aude A1 Cäsar, Cristiane A1 Neumann, Christof A1 Zuberbühler, Klaus YR 2019 UL http://advances.sciencemag.org/content/5/5/eaav3991.abstract AB Previous work suggested that titi monkeys Callicebus nigrifrons combine two alarm calls, the A- and B-calls, to communicate about predator type and location. To explore how listeners process these sequences, we recorded alarm call sequences of six free-ranging groups exposed to terrestrial and aerial predator models, placed on the ground or in the canopy, and used multimodel inference to assess the information encoded in the sequences. We then carried out playback experiments to identify the features used by listeners to react to the available information. Results indicated that information about predator type and location were encoded by the proportion of B-call pairs relative to all call pairs of the sequence (i.e., proportion of BB-grams). The results suggest that the meaning of the sequence is not conveyed in a categorical but probabilistic manner. We discuss the implications of these findings for current theories of animal communication and language evolution.