Abstract # 104:

Scheduled for Friday, June 21, 2013 11:00 AM-11:15 AM: Session 11 (San Geronimo Ballroom B) Oral Presentation


WHAT DO CHIMPANZEES (PAN TROGLODYTES) KNOW ABOUT TIME? ASSESSING EVIDENCE FROM FORAGING TASKS

C. R. Menzel and K. A. Sayers
Language Research Center, Georgia State Univ., Decatur, GA 30034, USA
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     Chimpanzees detect changes in the environment during their daily ranging. Field workers have speculated that chimpanzees notice unripe foods on day 1 and return to the locations on day 1+x when the foods are ripe, and that this strategy is based on a well-developed time sense. Recent studies clarify how chimpanzees use temporal cues along with other types of information relevant to foraging. We review results from about 20 experimental simulations of foraging problems, using captive chimpanzees. In single-object delayed-response tests of recall memory conducted in a small forest, a chimpanzee distinguished between times at which an object was present versus absent, showing a basic form of behavioral orientation in time. In multiple delayed-response problems with 2-20 targets in the forest, chimpanzees prioritized their recovery of food items by proximity, quantity, quality, and expected processing time, in a flexible manner. Under some conditions they also used temporal cues adaptively, placing significant weight on the relative recency (or the relative temporal distance) of the event. The weight placed on relative recency depended, in part, on the range over which each concurrent factor was varied and on the temporal properties of the objects. The view that all primates other than humans are trapped in present time is clearly incorrect. Supported by R01 HD-056352 and P01 HD-060563.