Inducing traditions in captive capuchin monkeys ( Cebus apella)

Abstract

Potential foraging and social traditions have been identified in groups of wild capuchin monkeys (Cebus spp.). Verification of traditions requires documentation that socially mediated learning contributes to acquisition by new practitioners. We investigated the emergence and maintenance of a foraging tradition in two generations of infant tufted capuchins (Cebus apella) in captive social groups. In baseline, we provided the first cohort of infants with a foraging apparatus that dispensed juice via two methods inside a small enclosure away from adult interference (the creche). Later in phase 1, we provided a second apparatus to all group members with only one method of solution available (in the group setting); the creche apparatus, with both methods available, remained accessible to infants only. Two years later (phase 2), we replicated phase 1 with a new cohort of infants from the same social groups. As adult activity and expertise with the apparatus increased across baseline (no adult activity), phase 1 (initially unskilled) and phase 2 (initially skilled), the proportion of infants in each cohort that acquired the foraging skill increased and their latency to skill acquisition decreased. Despite ambiguous evidence that the infants conformed to the specific method of solution common in their group, the social context clearly contributed to the development and maintenance of a general foraging tradition. The results provide support for the existence of traditions in wild capuchin groups.