Abstract Self-medication occurs across diverse taxa, but identifying novel behaviours and medicinal resources remains challenging due to the need for long-term observation, intensive health monitoring, and costly pharmacological analyses. Recent advances in analytical methods have enabled the development of the self-medicative resource combination hypothesis (SMRCH), which proposes that non-human animals may deliberately combine therapeutic resources when ill. This framework has previously been applied to identify non-random dietary combinations in wild chimpanzees. Here, we extend this approach to another great ape by examining dietary combinations in wild Bornean orangutans ( Pongo pygmaeus ), a species with emerging evidence of medicative feeding behaviour, thereby enabling broader comparative insight into medicative feeding across great apes. Using long-term feeding data from a Sebangau peat-swamp forest Central Kalimantan, we analysed patterns of plant use and evaluated their potential medicinal relevance. Our analyses revealed non-random dietary combinations involving plant species with documented ethnomedicinal and pharmacological properties. These findings are consistent with the SMRCH, supporting its utility as a framework for identifying non-random dietary associations that may represent candidate self-medicative behaviours in orangutans and other great apes. This research highlights the importance of preserving Indigenous knowledge for biodiversity conservation and global health research.
Allen et al. (Wed,) studied this question.