Abstract # 143:

Scheduled for Sunday, September 14, 2014 07:00 PM-09:00 PM: Session 22 (Decatur B) Poster Presentation


EFFECTIVE TOOL CHOICE BY CHIMPANZEES (PAN TROGLODYTES)

L. M. Mahovetz1 and W. D. Hopkins2,3
1Georgia State University, Department of Psychology, Atlanta, GA 30302, USA, 2Neuroscience Institute, Georgia State University, Atlanta, GA, 30302, 3Yerkes National Primate Research Center, Atlanta, GA, 30322
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     The ability to use tools is important for survival (Wagman & Carello, 2001) as tools aid in exploiting otherwise unattainable resources (Torrence, 1983; Foley, 1991). Previous research has shown that captive chimpanzees choose tools based on properties of weight (nut-cracking: Shrauf et al., 2012) and length (probing: Sabbatini et al., 2012). Here, we aimed to determine whether chimpanzees utilize tool properties beyond weight and length, and if flexibility is exhibited in selecting effective tools when property requirements change. Eleven captive chimpanzees were presented opaque PVC pipes modified to require use of specific tools based on properties of length (utilized as a baseline for comparison), surface area, shape, and rigidity. Regression analyses indicated performance on the length task did not predict performance on surface area, shape, or rigidity tasks (all p=ns). Paired t-test analyses revealed significant differences in performance in correct trial one choices between length and shape (t(10)=3.464, p=.006), surface area and shape (t(10)=5.164, p<.001), and surface area and rigidity (t(10)=2.887, p=.016) tasks. There were also significant differences in overall performance between length and both shape (t(10)=2.995, p=.013) and rigidity (t(10)=2.735, p=.021) tasks, and between surface area and rigidity (t(10)=-2.358, p=.04) tasks. These comparisons show that, although performance was best when length was the required property, chimpanzees are able to use properties of surface area, shape, and rigidity to exploit resources.