As a part of growing up, immature orangutans must acquire vast repertoires of skills and knowledge, a process that takes several years of observational social learning and subsequent practice. Adult female and male orangutans show behavioral differences including sex-specific foraging patterns and male-biased dispersal. Ehmann et al. investigated how these differing life trajectories affect social interest and emerging ecological knowledge in immatures. They analyzed 15 years of detailed observational data on social learning, associations, and diet repertoires of 50 immatures (16 females and 34 males), from two orangutan populations. Specific to the feeding context, they found sex differences in the development of social interest: Throughout the dependency period, immature females direct most of their social attention at their mothers, whereas immature males show an increasing attentional preference for individuals other than their mothers. When attending to non-mother individuals, males show a significant bias toward immigrant individuals and a trend for a bias toward adult males; in contrast, females preferentially attend to neighboring residents. These results suggest that immature orangutans show attentional biases through which they learn from individuals with the most relevant ecological knowledge. Diversifying their skills and knowledge likely helps males when they move to a new area. The image shows Cinnamon peering at her mother Cissy, who is using a stick tool to get honey out of a tree hole.

Image Credit: Guilhem Duvot