Department of Anthropology, The Ohio State University
Thursday 3:30-3:45, Ballroom B
Females in a variety of catarrhine species produce elaborate vocalizations, or copulation calls, in conjunction with maximal swelling tumescence and male ejaculation. One reasonable hypothesis is that copulation calls function to incite male competition. However, new data indicate that in some species these calls may instead function to encourage mate-guarding from consort partners and therefore evolved as a mechanism of female mate choice. As a preliminary test of this hypothesis, we recorded female copulation calls during 90 copulations involving 8 females and 10 males in 2 troops of wild olive baboons (Papio anubis) at Gombe Stream National Park, Tanzania. The olive baboon offers an interesting opportunity to test the female choice hypothesis because male olive baboons of all ranks follow consorting pairs and compete for access to viable females. In the current study, males were observed contesting consorts during nearly half (n=34) of all observed consorts (n=73). If calls function as a signal to male partners to continue consorting, it is likely that female calls are related to whether a consort is contested. Females called more often during uncontested than contested copulations (χ2=4.452, df=1, p<0.05), and when their male partner was high-ranking versus low-ranking (χ2=4.735, df=1, p<0.05). Variability in individual female’s acoustic patterns based on partner rank and time in female's cycle is addressed. Our results lend support for the female choice hypothesis for the evolution of copulation calls, and demonstrate that female mate preferences can be reflected in behaviors outside of those typically incorporated in female choice studies.
We would like to thank the following organizations and institutions for contributing to the funding of this project: The Leakey Foundation, International Primatological Society, American Society of Primatologists, Sigma Xi, Animal Behavior Society, and The Ohio State University Department of Anthropology.