Researchers observed an orangutan named Rakus in a rainforest in Sumatra, Indonesia, with a significant wound below his right eyelid and another one inside his mouth. They discovered that Rakus was chewing on the leaves of a particular liana plant known to humans as a pain reliever and even applied a paste made from the leaves to his face. This behavior of using leaves as a poultice for wound treatment was the first documentation of external self-medication in animals.
The wound on Rakus never became infected and healed within a week, which suggests that orangutans are capable of identifying and using pain-relieving plants. Researchers believe that this ability may trace back to a shared ancestor with humans. The discovery was made in the Suaq Balimbing research area, a protected rainforest in Indonesia’s Gunung Leuser National Park, where about 150 orangutans reside. Rakus, who has been observed since 2009, is either a resident or frequent visitor to the area.
Scientists have been observing orangutans in the Suaq Balimbing research area since 1994, following individual orangutans from early morning until they build a new nest at night. The researchers were surprised by Rakus’ behavior of self-medication, as they had not previously observed orangutans engaging in such activities in the area. Rakus may have learned to treat his wound through individual innovation or cultural learning from other orangutans.
Evidence of animal self-medication has been increasing in recent years, with examples such as chimpanzees using specific plants to prevent parasites or treat sickness. The ability of animals to self-medicate demonstrates their control over their lives and adaptive behavior. This behavior may have influenced ancient humans in identifying medicinal plants and substances by observing animals and learning from their actions.
Researchers believe that ancient humans may have learned about medicinal plants from animals, as many of the plants used by animals for self-medication are also used by humans. Rakus’ behavior of using leaves as a poultice for wound treatment may offer insight into how ancient primates, including humans, developed their inclination for pursuing medicines. Orangutans, which are considered critically endangered, can provide valuable information about the natural world and the importance of conservation efforts.
The findings from the study conducted on Rakus could shed light on the evolutionary roots of self-medication behaviors in animals and humans. The rainforests where Sumatran orangutans live are facing threats from deforestation, agriculture, and climate change, which are endangering the survival of these species. By studying behaviors like self-medication in orangutans, researchers can learn more about the interconnectedness of species and the importance of preserving natural habitats for the survival of endangered animals like the orangutans.
