Previous studies have found that chimpanzees often give food-associated vocalizations when they find food, and that these vocalizations may provide other chimpanzees with information about the amount and quality of the food that has been discovered. This study will use a combination of experiments with captive chimpanzees and observations of wild chimpanzees to solve a long-standing puzzle: given that chimpanzees often compete over food, why should they provide other chimpanzees with such information about food that they have found? This study will test the central hypothesis that chimpanzees benefit from giving these calls, not by sharing food, but by coordinating their travel with valued group members. Experiments with captive chimpanzees will test whether chimpanzees that hear recordings of food-associated vocalizations from other chimpanzees increase their own foraging effort. Observations of wild chimpanzees are expected to show that chimpanzees call more frequently when with valued members of their group, such as mates and allies, and that when chimpanzees hear such calls, they spend more time searching for food in a given spot. This research will result in a greater understanding of the role food-associated communication play in the social foraging decisions of chimpanzees. By approaching the puzzle of food-associated call production from a social decision-making perspective, these studies will transform our understanding of this calling behavior while simultaneously providing novel insight into the role communication plays in social decision-making processes.
