Meaningful call combinations in a non-human primate

We conducted a series of playback experiments with free-ranging putty-nosed monkeys at Gashaka Gumti National Park, Nigeria. In a first experiment, we observed the behavior of the females of a habituated group in response to playbacks of natural call series of their own male. A female could serve as focal subject if she was located at the periphery of the group while the male was at the opposite side, hereby ensuring that the male’s calls emanated from the correct direction. Playback trials consisted of five ‘hacks’, five ‘pyows’ or a five-call P–H sequence. Using a GPS unit, the focal female’s location was marked prior to and 20 min after playback, while her behavior was monitored continuously. Our results showed that playback of ‘hack’ series (usually indicating eagle presence) inhibited movement in females (median = 1.0 m) and Meaningful call combinations in a non-human primate