Abstract: Research on primate cognition has spurred interest in developmental influences on skill acquisition, especially complex foraging skills in great apes and specifically as they relate to species' life history strategies. Survival skills are often mastered to functional levels near the onset of juvenility, for instance, this is when immatures are weaned and assume semi-independent lives. Several complications merit consideration: primate learning is lifelong; learners' situations change well beyond weaning; and individual tasks can vary such that they create rich problem spaces, mastering which entails acquiring and coordinating multifaceted skill sets. Accordingly, while skills may reach functional levels by weaning, they may be refined later. Juveniles, adolescents, and young adults, in particular, should generate such refinements given the developmental changes they experience in learning needs and opportunities, physical and cognitive abilities, and sociality. To assess acquisition beyond weaning, this study tracked the acquisition of foraging skills for extracting heart from a tree palm (Borassodendron borneensis) in juvenile and adolescent rehabilitant orangutans. Findings represent 744 cases of palm heart extraction, 31 rehabilitants ranging in age from older infants to young adults, and two forests in Indonesian Borneo. Data were collected observationally over 9 y and include partial longitudinal data for 14 rehabilitants. Results highlight the importance of fine-grained assessments of both behavior and problem space in understanding developmental influences on the acquisition of sophisticated foraging skills in great apes. Implications for the study of cetacean cognition are suggested.
Key Words: ORANGUTAN; GREAT APES; COGNITION; FORAGING; DEVELOPMENT; LEARNING; SKILLS
Document Type: Research article
Page Numbers: 500 - 510