Jill Daphne Pruetz

Grant Type

Post PhD Research Grant

Institutional Affiliation

Texas State U.

Grant number

Gr. 9473

Approve Date

April 25, 2017

Project Title

Pruetz, Dr. Jill Daphne, Texas State U., San Marcos, TX - To aid research on 'How Do Spear-hunting Chimpanzees (Pan troglodytes virus) Adjust to Prey Behavior at Fongoli, Senegal?'

Preliminary abstract: Chimpanzees (Pan troglodytes verus) living in a savanna environment at Fongoli, Senegal are the only known mammalian population besides humans that hunt with tools. Chimpanzees here use modified stick tools (‘spears’) to hunt nocturnal prosimians (Galago senegalensis) as they nest in tree cavities during the day. Additionally, females hunt significantly more than expected with tools, while males hunt significantly less, unlike the male-dominated hunting at all other sites where chimpanzees have been studied. With more than 400 cases now recorded, we better understand sex differences in tool-assisted hunting, but additional questions remain. Such hunting is concentrated in the early rainy season, which we initially interpreted as a consequence of increased contest competition during a period when the entire study community ranges together. Female and adolescent chimpanzees’ increased hunting could be a strategy to give them access to preferred food. Testing this hypothesis as well as alternative ones related to the abiotic, biotic and social environment are critical to better understanding this unique hunting pattern, which has implications for the evolution of hunting in early hominins. Much of the data necessary for hypothesis testing are in hand, but data on prey species availability are lacking. I propose to test the opportunity and necessity hypotheses to explain tool use, which require data on Galago cavity use on a seasonal basis, as well as cavity use on a shorter temporal scale (e.g., after rainfall). In general, the proposed study promises to better inform our understanding of predator-prey relations in primates, ecological influences on hominoid hunting behavior and, subsequently, contributes to generating hypotheses about the origins of hunting in early hominins.