Spatio-Temporal Cognition & Foraging

Chimpanzee spatio-temporal cognition and foraging: The view that there is something fundamentally different about human and nonhuman memory dates back more than 20 centuries. It is a perspective shared today by a number of prominent philosophers, psychologists, and biologists. The ability to recall and “tell” cooperative group members about distant resources presumably became important for early human hunters and gatherers. Until recently, however, there have been almost no data on recall and reporting capabilities of this sort in chimpanzees. Support from the Leakey Foundation helps Dr. Charles Menzel and Dr. Ken Sayers study chimpanzees’ abilities to recall and report, via lexigrams, the types of objects they saw hidden hours or days earlier in a small wood. We test Language Research Center chimpanzees’ abilities to rank order (prioritize) a set of hidden, spatially dispersed foraging targets according to food item quantity, type, and distance. We also study how the apes use temporal information (information about the relative recency of events) in combination with information on food stability and specific location to optimize the order in which they obtain the foods. The tasks simulate the conditions under which a wild chimpanzee needs to remember multiple foods, locations, and events. The data obtained allow us to characterize episodic recall, flexible use of memory cues, and efficiency of foraging sequences in a more detailed way than was possible in the past. A comparative perspective of memory helps in modeling human origins and early human foraging patterns. For example, our findings on chimpanzees have been used, along with other forms of evidence, to model the foraging behavior and diet of Ardipithecus.