What the extraordinary medical know-how of wild animals can teach us

Two decades ago, Jaap de Roode made a discovery that changed his scientific career. While researching the ecology and evolution of parasites and their hosts, he came across something truly surprising: the monarch butterflies he was studying seemed to be exploiting the medicinal properties of plants to treat themselves and their offspring.

Back then, the notion that an insect might be capable of self-medicating seemed far-fetched. Now, de Roode is a world expert in the burgeoning field of animal medication, with a lab of his own at Emory University in Atlanta, Georgia. He spoke to New Scientist about his work, his new book, Doctors by Nature: How ants, apes and other animals heal themselves, and his belief that animals possess medicinal knowledge that we can use to improve our own health.

Graham Lawton: How did this unlikely area of research get going?

Jaap de Roode: It started during work in Tanzania in the 1980s with a chance observation. Michael Huffman of Kyoto University was working with Mohamedi Seifu Kalunde, a national parks ranger, to look at the role of elderly chimpanzees in society. While tracking one called Chausiku, they noticed that she was withdrawn, she was taking naps during the day and she had diarrhoea. They saw her go to a plant called Vernonia, also known as bitter leaf. She stripped off the bark and started sucking the pith. This is not normally part of their diet. Seifu, who was also a traditional healer, told Huffman that he uses it as a…