1Department of Anthropology, University of Michigan, 2Department of Psychology, University of Michigan, 3Human Genome Sequencing Center, Baylor College of Medicine, 4Department of Anthropology, New York University, 5Department of Anatomy and Neurobiology, Washington University School of Medicine, 6Department of Anthropology, Washington University
Thursday Afternoon, 301D
Recently, it was shown that male testosterone profiles from three non-seasonally breeding primates (yellow baboons, Papio cynocephalus, chacma baboons, P. ursinus, and geladas, Theropithecus gelada) track life history variables, including the start and end of the reproductive period within the lifespan. Here, we examine testosterone profiles from male kinda baboons (Papio kindae), a species whose life history and reproductive behavior are little known. We use age-specific testosterone profiles from these other three species to speculate on the reproductive trajectory of kinda males. Testosterone was extracted from fecal samples (N=30) collected during trapping conducted in 2011 near Chunga Camp, Kafue National Park, Zambia. Ages of males were estimated from dental eruption and wear patterns. Overall, results indicate that kinda male testosterone profiles exhibit the typical inverse-U pattern across age. Kinda males exhibit adult levels of testosterone at an earlier age (~5 y) than the other three species. Additionally, kinda males demonstrate sustained levels of testosterone into older age categories. To the extent that high testosterone is associated with reproductive activity, the kinda profile suggests that males may mature earlier than other closely-related species. Further, rather than a discrete window of testosterone secretion (and reproduction, as exhibited by geladas and chacma baboons), kinda males continue to have elevated testosterone beyond prime age categories (similar to yellow baboons). If further samples confirm this profile, then this suggests that kinda baboons may not have high reproductive skew associated with male dominance. Confirmation of this prediction will have to await longitudinal behavioral data.
Funding was provided by the National Science Foundation (BCS 1029403).