Learning to Live, or Living to Learn?Age-related differences in foraging behavior and the extended juvenile period of Cebus capucinus

by Morgan Edward Chaney

Institution: Kent State University
Department: College of Arts and Sciences / Department of Anthropology
Degree: MA
Year: 2015
Keywords: Animals; Behavioral Sciences; Biology; Cebus capucinus; juvenile period; needing to learn; foraging ontogeny
Record ID: 2057967
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=kent1428846210


Compared to other primates, capuchin monkeys have large brains and a protracted juvenile period. According to the needing-to-learn hypothesis for the evolution of extended juvenile periods, longer juvenility may be necessary for acquiring the extractive-foraging behaviors that these monkeys use to exploit hidden or well protected foods. I tested three predictions of this model with observational data on the behavior of free ranging Cebus capucinus at Estacion Biologica Piro on the Osa Peninsula, Costa Rica. Compared to the number of instantaneous scans devoted to feeding, small juveniles (approx. 1-3 years) devoted the greatest proportion of scans to foraging, followed in increasing order by large juveniles (approx. 3-5 years), adult males, and adult females. After correcting for multiple comparisons, however, large juveniles were not statistically different from adult males in this measure. Small juveniles appeared unable to follow the adult technique for processing the palm fruits of Attalea butyracea (Arecaceae), and large juveniles spent significantly more time processing each fruit than did adult males and females. No predicted differences in social foraging or diet were evident during this study. In all, these findings do not show support for a foraging-focused formulation of the needing-to-learn hypothesis, but capuchins have more to learn before adulthood than foraging skills. A model that included social behaviors would likely better explain the evolution of an extended juvenile period in these encephalized monkeys.