Data from: Social familiarity of the signaller affects responses to alarm calls in habitat-specific ways in wild Diana monkeys (Cercopithecus diana diana)

Male Diana monkeys produce loud and acoustically distinct alarm calls to leopards and eagles that propagate over long distances, much beyond the immediate group. Moreover, males regularly respond to each other’s alarm calls, even if the caller is far away, suggesting an additional function of these alarm calls in male-male competition. Here we tested whether Diana monkeys discriminated familiar from unfamiliar callers in two populations in Taï Forest (Ivory Coast) and Tiwai Island (Sierra Leone) and whether this discrimination is indicated differently across populations. Additional to socially related information (familiarity of the signaller), we simultaneously provided listeners with information about a nearby threat by broadcasting conspecifics’ alarm calls to see whether familiarity of the signaller also has an impact on anti-predation behaviour. We found that male Diana monkeys generally discriminate conspecific alarm calls on the basis of familiarity but that they also integrate information about predator presence into responses and that this assessment is indicated by different acoustic features in both habitats. Furthermore, we show that responses to conspecific alarms are not rigidly fixed in a species but a result of incorporating and processing various information about a given ecological setting leading to consistent population differences in responses to conspecific alarm calls.