Development of skilled detection and extraction of embedded prey by wild brown capuchin monkeys (Cebus apella apella).

Brown capuchin monkeys (Cebus apella apella) in Suriname forage on larvae enclosed within healthy bamboo stalks. We applied the searching versus handling dichotomy of optimal foraging models to highlight developmental processes contributing to foraging on embedded prey. Larvae acquisition begins with search; selecting an appropriate stalk and locating the embedded larvae; followed by handling, ripping the stalk open, and extracting the larvae. Although extraction behaviors were present at low rates in infant capuchins' repertoire, we found that the acquisition of adequate detection techniques was fully completed in subadults, aged around 6. Selecting appropriate foraging substrates, requiring accurate assessment of the physical properties of bamboo stalks, gradually increased with age and experience. We showed that both components of searching required extended practice beyond that required to master the handling components. We conclude that the developmental sequence of skill acquisition goes counter to the preceding logical sequence of foraging process and suggest that searching components present greater challenges than handling components in extractive foraging. Specifying the searching components of foraging more precisely will enhance understanding of species variation in the developmental schedule of foraging skills.