Orangutans concoct plant-based soothing balm

Great apes show medicinal savvy

Indonesian wild orangutans have demonstrated a certain degree of medicinal savvy by deploying naturally-occuring anti-inflammatory drugs to "treat aches and pains", as the New Scientist puts it.

Four of the Bornean orangutans (Pongo pygmaeus) were spotted by Cambridge University primatologist Helen Morrogh-Bernard in the Sabangau Peat Swamp Forest in Central Kalimantan preparing a "soothing balm".

Back in 2005, Morrogh-Bernard watched as an adult female picked a handful of leaves from a plant, chewed them, and used saliva to produce a green-white lather. She then "scooped up some of the lather with her right hand and applied it up and down the back of her left arm, from the base of the shoulder to the wrist, just as a person would apply sunscreen".

Morrogh-Bernard noted: "She was concentrating on her arm only and was methodical in the way she was applying the soapy foam. I knew this must be some form of self-medication."

The orangutan finally ditched the leaves, which allowed Morrogh-Bernard to identify them as belonging to the genus Commelina. Significantly, orangutans don't eat these plants as part of their normal diet, and local indigenous people are also aware of their anti-inflammatory properties.

Morrogh-Bernard has since clocked three other orangutans using their home-brew balm, saying it "links apes and humans directly". While she said the former "may not have learnt how to apply the anti-inflammatory ointment from local people", the opposite may be true.

Morrogh-Bernard's findings are published in the International Journal of Primatology. ®