The goal of the proposed study is to detail the form and function of vocal communication and antipredator behavior in two species of lemur. These two primate species are ideal for this comparative study because they differ in size, sociality, ecology and reproductive biology. Their vocal repertoires will be quantified, the importance of visual and auditory cues used to discriminate harmful from harmless animal stimuli will be determined, and alternative hypotheses of antipredator call function will be tested through predator model presentations and call playback trials. The project will be conducted in a large natural habitat enclosure using models of naturally-occurring avian and mammalian predators as stimuli. %%% Predation pressure is recognized as having had a profound impact on primate social organization, yet vocal and non-vocal antipredator tactics of primates have received little research attention. This project addresses a central issue in the study of nonhuman primate vocal communication, and does so in a way that is likely to make an important contribution to current theories concerning the evolution of human language.
