How wild apes treat their own wounds

Rakus and the yellow-root liana

In June 2022 at the Suaq Balimbing research area in Aceh, Indonesia, primatologists following a flanged male Sumatran orangutan named Rakus noticed a deep open flesh wound on his right facial flange, likely suffered during a vocalized fight with a rival male. Three days later, Rakus did something never before documented in a wild animal: he selectively stripped leaves from a climbing liana known locally as akar kuning (Fibraurea tinctoria), chewed them without swallowing, dabbed the liquid juice onto the open wound for seven minutes, and then packed the injury completely with the chewed leaf mash. [1][2][3]

• Rakus chewed Fibraurea tinctoria leaves without swallowing and dabbed the liquid juice onto his facial wound for seven minutes
• He then covered the exposed flesh completely with a poultice of chewed leaf pulp and rested more than usual while healing
• Suaq orangutans eat this bitter liana on fewer than 0.3% of feeding scans, underscoring the selectivity of the behavior

A plant with real pharmacology

Fibraurea tinctoria is widely known in Southeast Asian ethnomedicine, and phytochemical assays show that its stems and leaves contain high concentrations of furanoditerpenoids and protoberberine alkaloids—including berberine and jatrorrhizine—with laboratory-confirmed antibacterial, anti-inflammatory, antifungal, analgesic, and antioxidant activity. Whether Rakus was guided by immediate pain relief or learned tradition, the clinical outcome was striking: the open facial wound showed zero signs of secondary infection in the humid swamp forest, closed completely within five days, and left only a faint scar one month later. [1][3][4]

• Fibraurea tinctoria contains furanoditerpenoids and protoberberine alkaloids with antibacterial and analgesic effects
• Immediate pain-relieving or cooling sensations on inflamed tissue may reinforce repeated topical application
• Rakus's deep facial wound showed no sign of infection, closed within five days, and healed with minimal scarring

Chimpanzee first aid

At the Budongo Forest Reserve in Uganda, an Oxford-led team combined eight months of field observations across two neighboring chimpanzee communities (Sonso and Waibira) with three decades of logbook records and video archives. They catalogued 41 cases of active wound care and hygiene, including wound licking, finger pressing, dabbing injuries with folded green leaves, and applying chewed plant material directly to cuts. Seven cases involved prosocial care of another chimpanzee's injury—three of them between genetically unrelated troop members—and extracts of several selected plants, such as Alstonia boonei, showed strong antibacterial potency in lab assays. [5][6]

• Budongo researchers documented 41 cases of chimpanzee wound care and hygiene across two wild communities
• Chimpanzees treated both their own injuries and the wounds of seven companions, including unrelated troop members
• Laboratory assays confirmed that several plants dabbed or chewed by the chimpanzees inhibit wound-infecting bacteria

What it means, and what it does not

Because Rakus treated only his facial wound and no other body part, repeated the application over more than thirty minutes, and selected a rarely eaten medicinal liana, the authors argue that topical wound care was intentional and that evolutionary precursors of human medicine trace back to the common ancestor of hominids. Two essential caveats apply: field observations of wild ape self-medication are rare natural-history records rather than clinical trials, and wild tropical plants can be toxic to humans if ingested or applied without pharmacological testing. [1][3][6]

• Targeted, prolonged application to the wound alone indicates intentional topical treatment rather than accidental contact
• Shared self-medication behaviors across orangutans, chimpanzees, and humans point to deep evolutionary roots in hominids
• Field observations describe wild animal behavior and are never a basis for human herbal or medical self-treatment

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