Aimed Throwing as a Means of Food Transfer Between Tufted Capuchins (Cebus apella)
Source: International Journal of Primatology, Volume 19, Number 1, February 1998 , pp. 123-131(9)
Abstract:We examined aimed throwing as a means of food transfer in tufted capuchins (Cebus apella). We conducted this research in three phases. In Phase 1 we provided food to monkeys in one of two groups housed 1 m apart. We did not provide food to subjects in the second group. An observer recorded each instance in which a subject in the first group threw food toward one in the second group. In Phase 2 we provided a group of capuchins with food and noted each instance in which a subject threw food toward an empty cage. In Phase 3 we provided food simultaneously to two groups of capuchins and noted each instance of food-throwing between them. In Phase 1 subjects in one group threw food toward subjects in a second group, which, when provided the opportunity, did not throw food toward capuchins in the first group. Thrown food was either caught, retrieved, or lost on the test room floor. The rate of throwing decreased significantly when subjects were presented with an empty cage and when both groups of subjects were given food. We propose that psychological processes which underlie aimed throwing and food sharing came into existence through convergent evolution in large-brained, extractive foraging primates. We further speculate that although a well-developed system of exchange, based on contingent reciprocity, may occur among primates only in Homo,simpler transfer systems involving voluntary unidirectional passing of food from one individual to another appear to be more widespread among primates than previously thought and can be expressed in rather unusual circumstances such as those in this experiment.
Document Type: Research Article
Affiliations: 1: Laboratory of Comparative Ethology, National Institute of Child Health and Human Development, Bethesda, Maryland. National Institutes of Health Animal Center, Poolesville, Maryland 20837 2: Laboratory of Comparative Ethology, National Institute of Child Health and Human Development, Bethesda, Maryland 3: School of Psychology, University of St. Andrews, St. Andrews, Scotland
Publication date: February 1, 1998