Migrant orangutan males use social learning to adapt to new habitat after dispersal

Abstract

Dispersal has been suggested to be challenging, especially for species that heavily rely on social learning for knowledge acquisition. One of the obstacles that migrants face is learning how to cope with an unfamiliar, new habitat, which may involve learning from resident individuals. So far, only very few studies have looked at social learning in migrants after dispersal. Here we examine how migrant male orangutans use a behavior called “peering” (an indicator of observational social learning), to learn from local individuals. In total, we analyzed 4,009 daily dyadic associations with and without peering events of 77 males of the highly sociable Sumatran orangutans (Pongo abelii) at the Suaq population and 75 males of the less sociable Bornean orangutans (Pongo pygmaeus wurmbii) at the Tuanan population, covering a combined study time of 30 years. Analysis using generalized linear mixed models supported our prediction that migrant males in Suaq preferentially peered at the local adult females. However, in Tuanan, migrants peered mostly at other adult males and local immatures. Migrants’ peering rates were highest shortly after their arrival, and significantly decreased with increasing time spent in the area. Migrants in both sites peered significantly more at peering targets’ feeding on food items that are rarely eaten within the locals’ diet, than at commonly eaten ones and peered significantly more at skill-intense food items than easy-to-process ones. Further, migrants interacted significantly more with the peered-at food item after the peering event, than before, suggesting that they practice the observed behavior. Our results therefore suggest that migrant males use peering to learn new ecological knowledge after dispersal (e.g., where and what to feed on), and continue to learn complex skills even within adulthood, (e.g., how to feed on skill-intense food items). To do so, migrants selectively attend to the most knowledgeable and/or available individuals, practice the new skill afterwards and even flexibly adjust their learning, e.g., when confronted with intolerant locals or when the need for learning decreases. Together, our study provides important evidence that social learning in great apes expands towards adulthood, an ability which critically impacted also human evolution.

Alternative reproductive tactics of unflanged and flanged male orangutans revisited

“…Second, unflanged male sociality may also serve to establish longterm relationships with females , which may eventually lead to higher reproductive success. Third, sociality of recently dispersed unflanged males may not only serve reproductive strategies but also acquisition of local ecological skills (Mörchen et al, 2023). The observed decrease in female associates with years since first observation in the crosssectional dataset may provide evidence for the latter two explanations of unflanged male sociality.…”

Active self-treatment of a facial wound with a biologically active plant by a male Sumatran orangutan

“…As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times and subsequently apply solid plant matter possibly to also cover the wound as a protection against flies (as the case reported here suggests). Immature orangutans rely on observational social learning for the acquisition of their skill repertoires 64 and recent evidence suggests that social learning continues into adulthood 65 . Therefore, given that it occurs frequent enough and in social contexts, wound treatment with Fibraurea tinctoria may also spread socially from individual to individual.…”

Cultural evolution: A review of theoretical challenges

“…The variety of animal species examined as well as evidence of performances with basic cultural features have markedly increased. Ethological research has produced studies on the pace of animal innovations, as found in seasonal changes in songs of humpback whales (Schulze et al, 2022 ), on cultural transmission in the manufacture of tools, as in New Caledonian crows (Hunt & Gray, 2003 ), and on the adoption of new behavioural elements from resident individuals when they must adapt to new habitats after dispersal, as in male orangutans (Mörchen et al, 2023 ). The current state of the field suggests that there is a variety of basic cultural performances in a wide array of animal orders from invertebrates to birds and mammals (Whiten, 2021 ) and that the number of (unspecified) cases of ‘culture’ is underestimated (Schuppli & Van Schaik, 2019 ).…”