Acceptance of novel foods in capuchin monkeys: do specific social facilitation and visual stimulus enhancement play a role?

Abstract

Living in groups, as most primate species do, can be of great advantage in learning when, how and on what to feed. We tested the hypothesis that social influences foster the acquisition of a safe diet; we investigated whether in tufted capuchins, Cebus apella, social influences on novel food consumption (already demonstrated for this species) are stronger when the physical characteristics of the food eaten by group members and the novel food presented to the subject are the same. In experiment 1, we investigated whether group members eating a food of the same colour makes a novel food more acceptable to the subject than group members eating food of a different colour; in experiment 2, we provided the subject with a choice between a bowl with novel food whose colour matched the food eaten by group members and a bowl with novel food whose colour did not match. Subjects spent more time eating the food matching the colour of the group members' food, but did not ingest more of it (experiment 1) and, when given a choice, did not eat the matching food more than the nonmatching food (experiment 2). Therefore, since social influences were not directed to a specific food target, the hypothesis that these foster the individual's diet acquisition is not supported. Instead, our results support the view that social influences increase acceptance of novel foods or synchronize feeding activities.