The 85th Annual Meeting of the American Association of Physical Anthropologists (2016)


Predation by female chimpanzees at Gombe and Kibale: toward an understanding of sex differences in meat acquisition among early hominins

IAN C. GILBY1, ZARIN P. MACHANDA2, ROBERT C. O'MALLEY3, CARSON M. MURRAY3, DEUS C. MJUNGU4, EMILY OTALI5, MARTIN N. MULLER6, MELISSA EMERY THOMPSON6, RICHARD W. WRANGHAM2 and ANNE E. PUSEY7.

1School of Human Evolution & Social Change, Arizona State University, 2Department of Human Evolutionary Biology, Harvard University, 3Department of Anthropology, George Washington University, 4Gombe Stream Research Centre, The Jane Goodall Institute, 5Kibale Chimpanzee Project, Makerere University Biological Field Station, 6Department of Anthropology, University of New Mexico, 7Department of Evolutionary Anthropology, Duke University

April 14, 2016 9:15, A 706/707 Add to calendar

Since women often hunt, acquiring more meat than men in some contexts, it is surprising that hunting by females is rarely considered in human evolutionary scenarios. Chimpanzees are often used as referential models of early hominins. We use 55 years of data from two chimpanzee communities to test the hypothesis that due to constraints associated with raising offspring, females primarily target less dangerous and less risky prey than males do. Preliminary analysis of data from Kasekela (Gombe National Park, Tanzania) supports this hypothesis. There, females captured only 10% of the red colobus monkeys, 11% of the baboon infants, 21% of the bushpig infants, and 32% of the guenons killed during the study. Capturing these species involves considerable energy expenditure and/or confrontations with dangerous defenders. By contrast, females acquired 68% of the birds (mostly nestlings), 83% of the eggs, and 43% of the bushbuck fawns. These prey items are generally less costly to obtain, although on several occasions, females stole carcasses from adult male baboons. Overall predation was less frequent at Kanyawara (Kibale National Park, Uganda), and was almost entirely limited to arboreal monkeys, which were typically killed by males – females caught only 8% of the red colobus and 20% of the black and white colobus that were killed during the study. These results suggest that female hominins may have concentrated their efforts on low-cost hunts of concealed prey. We test the hypothesis further by examining individual variation in hunting proclivity and the circumstances under which females capture high-risk prey.

Funding provided by the Jane Goodall Institute, the National Science Foundation (9021946, 9319909, 0452315, 1052693, 1106401, 0431141, 9807448, 0416125, 1355014) and the National Institutes of Health (R01-AI058715, R00-HD057992).