Abstract # 182:

Scheduled for Friday, August 18, 2006 07:00 PM-09:00 PM: Session 17 (Regency West 1/3 ) Poster Presentation

Will capuchins (Cebus apella) work harder for a preferred food?

N. V. Morgan, C. A. Buzzell and K. A. Phillips
Hiram College, Department of Psychology, Hiram, OH 44234, USA
     The purpose of this study was to examine food preferences in capuchins (Cebus apella) and how such preferences would influence tool use. It was expected that preferred food items would engage subjects’ tool using abilities more then less-preferred foods. Five subjects were trained to use a hoe-like tool for retrieving a food reward from two-lane apparatus with an easy (1 barrier) and difficult (3 barriers) lane. In experimental trials (N=30) subjects were presented simultaneously with a choice of a preferred (grape) or less-preferred (orange) food, varied by their placement in either the difficult or easy lane. A Latin Square design was used to eliminate order and side effects. Regardless of barrier condition, all subjects spent significantly more time (Wilcoxon z(5) = -2.02, p<.05) and performed more tool manipulations (Wilcoxon z(5)= -2.02, p<.05) to retrieve the grape. Subjects retrieved the grape over the orange regardless of whether it was in the difficult (t(4) =10.96, p < .05) or easy lane (t(4) = 11.37, p < .05). These results indicate that capuchins will work harder for a preferred food reward and support the proposal that tool use may be elicited by desirable food items.