Wild chimpanzees drink alcohol using leafy tools, research finds

Wednesday, 10 June 2015

Chimpanzee drinking palm wine

Research by an Oxford Brookes academic and a team of international scientists has found that chimpanzees drink alcohol using leafy drinking vessels.

The paper, by Dr Kimberley Hockings has been published in the Royal Society journal Royal Society Open Science today (10 June)

In another recent study by US researcher Matthew Carrigan, humans and African apes have been found to share a genetic mutation that enables them to effectively metabolise ethanol. However, aside from enforced ingestion in captive experiments or anecdotal observations in wild apes, the habitual and voluntary consumption of ethanol has been documented only in humans, until now.

Some individuals were estimated to have consumed about 85ml of alcohol (which is the equivalent to 8.5 UK units) and displayed behavioural signs of inebriation.

Dr Kimberley Hockings, Researcher at Oxford Brookes University

The new research was headed by Professor Tetsuro Matsuzawa of the Primate Research Institute at Kyoto University, Japan and it provides the first empirical evidence of repeated and long-term ethanol ingestion by apes in nature. 

Wild chimpanzees in Bossou in the Republic of Guinea, West Africa, harvest fermented sap from the raffia palm using elementary technology – a leafy tool as a spongy drinking vessel. 

This absorbent extractive tool is dipped into the opening of the fermented palm sap container, then retrieved and put into the mouth for drinking. All age and sex classes ingested the fermented palm sap and some of the chimpanzees consumed high quantities of alcohol. 

Dr Kimberley Hockings from Oxford Brookes University and the Centre for Research in Anthropology (CRIA-FCSH/UNL) in Portugal, and lead author of the paper said: “Some individuals were estimated to have consumed about 85ml of alcohol (which is the equivalent to 8.5 UK units) and displayed behavioural signs of inebriation, including falling asleep shortly after drinking. 

“Our research demonstrates that there is not a strict aversion to food containing ethanol in this chimpanzee community. 

"This new use of elementary technology shows once again how clever and enterprising humankind’s nearest living relations are."

The video clip below shows an adult male chimpanzee in Bossou, South-eastern Guinea drinking palm wine.

Another recently published article by Dr Hockings explained how apes are adapting to living in human populations at an increasing rate. More can be read about this study on the University news webpages

Photo credit: G. Ohashi, Chubu University, Japan, and Wildlife Research Center, Kyoto University, Japan.

Video credit: M. Nakamura, Wildlife Research Center, Kyoto University, Japan.