Animals respond to novel stimuli showing explorative and/or neophobic behavior. The coexistence of these responses toward novel foods may be a successful adaptive strategy for a generalist species such as Cebus apella, because it allows the gradual introduction of new foods into the diet, and reduces the risk of poisoning by ingestion of large amounts of toxic compounds (Glander, 1982; Milton, 1993; Visalberghi, 1994). Neophobia has been studied mostly in captivity. We investigated responsiveness to novelty in a group of 25-30 wild tufted capuchins (Cebus apella) in Iguazú National Park (Argentina). This group had been habituated to visiting sites where bananas were provided on three elevated platforms. Novel stimuli were presented on an adjacent platform. There were 4 experimental conditions with ten sessions each: the Novel Food condition, the Novel Object condition, the Control condition (in which the platform was empty), and the Banana condition. In the Novel Food and Novel Object conditions, a new stimulus (food or object) was on the platform during each session. The Banana condition provided information on capuchins' response to a familiar preferred food. Overall, capuchins were less responsive toward novel objects than toward novel foods; however, although cautious, they did eat small amounts of the novel foods. Age affected the individuals responsiveness toward novel foods, whereas sex affected the responsiveness toward novel objects. Capuchins ignored the empty platform. Our findings are in agreement with the idea that tufted capuchins can adapt to new habitats by gradually exploiting new food sources.
