The alarm-calling system of adult male putty-nosed monkeys, <i>Cercopithecus nictitans martini</i>

We investigated the calls of male putty-nosed monkeys produced in response to playbacks of leopard,<i>Panthera pardus</i>, growls and crowned eagle, <i>Stephanoaetus coronatus</i>, shrieks. Two call types, hacks and pyows were produced and both occurred within alarm-calling sequences regardless of the predator category simulated by the playbacks. Unlike previous studies of alarm calling in guenon monkeys, we therefore could not conclude that the alarm calls of putty-nosed males are functionally referential. There were, however,striking regularities in the patterning of the calls given in response to these stimuli and different call combinations were strongly associated with each of the two predator types. While we concluded that individual calls did not qualify as vehicles of semantic content, these males produced structurally unique call sequences that provided sufficient information for receivers to select appropriate antipredator responses.