Abstract # 52:

Scheduled for Thursday, August 17, 2006 04:15 PM-04:30 PM: Session 6 (Regency East #3) Oral Presentation

A chimpanzee as a traveling salesman's director

C. R. Menzel1, J. W. Kelley1, S. A. Hunsberger1, B. Chan1 and E. W. Menzel2
1Georgia State University, Language Research Center, 3401 Panthersville Rd., Decatur, GA 30034, USA, 2SUNY, Stony Brook
     We hypothesize that free-living primates rank-order the expected value of visits to invisible resources that vary in quality, quantity and location and then, quite often, visit the resources sequentially according to their ranking. We test here a lab simulation of this task. A female lexigram-competent chimpanzee (Pan troglodytes) watched while an experimenter hid multiple goal objects outside her outdoor enclosure. Objects varied in quality, quantity, specific location, and relative distance. Later, the chimpanzee could interact indoors with a caregiver who did not know the types, quantities, locations, or distances of the objects. The chimpanzee conveyed the type of object hidden by touching lexigrams, and she directed the person to hidden goals, one at a time, by pointing from a tower. The order of recovery of goals revealed a stable criterion of ranking and was far more efficient than expected by chance (p<0.001). The ranking involved simultaneous use of quality, quantity, and spatial information. Analogous performances were shown by a male lexigram-competent chimpanzee. The ability to rank the profitability of resources on the basis of combined quality, quantity and distance, and the ability to implement sequential travel choices in a social context can be expected to improve the foraging efficiency of chimpanzees, baboons, and other social mammals in their natural habitat. Research supported by HD-38051, MH58855, and the Wenner-Gren Foundation.