Abstract # 4:

Scheduled for Thursday, August 17, 2006 10:00 AM-10:15 AM: Session 1 (Regency East #1) Oral Presentation


THE ONTOGENY OF FORAGING SKILLS IN WILD BROWN CAPUCHINS (Cebus apella), RALEIGHVALLEN, SURINAME

N. Gunst1, S. Boinski2 and D. Fragaszy3
1Institute of Ecology, University of Georgia, Athens, GA 30602-2202, USA, 2Department of Anthropology, University of Florida, Gainesville, FL, USA, 3Department of Psychology, University of Georgia, Athens, GA, USA
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     Capuchin monkeys are extractive and social foragers. They exhibit complex foraging behaviors that may require extensive learning to be fully mastered. Our study aimed at better understanding the developmental processes involved in the acquisition of foraging competence in brown capuchins (Cebus apella). Observations took place in Central Suriname Nature Preserve, from March 2003 to June 2005. During the observation period, the study group size varied from 25 to 29 individuals. We used focal-animal sampling, based on a total of 34 subjects, representing all age/sex classes. We focused on food sources and foraging techniques observed when the capuchins foraged in bamboo patches. We analyzed 661 hours of pen-and-paper 30-sec interval focal samples. We found significant differences according to age classes in: 1) the proportion of time spent searching for large larvae embedded in bamboo stalks, and 2) foraging success by ripping stalks apart (infants: 5.8%, 0.0%; young juveniles: 13.8%, 12.3%; older juveniles: 39.4%, 24.8%; subadults: 67.1%, 53.7%; adults: 41.2%, 51.9%, respectively, Kruskall-Wallis tests, p<0.001). During the acquisition of foraging competence, scrounging by unskilled individuals may enhance opportunities for social learning. Infants and young juveniles spent significantly more time scrounging from other group members than older individuals (p<0.001). From cross-sectional and longitudinal analyses, we found age differences in activity budget, foraging patterns and efficiency, and assessed the developmental changes in foraging in brown capuchins. Supported by NSF (BCS-0352035).