Wild chimpanzees in Guinea-Bissau have been observed sharing fermented fruit containing alcohol, in behaviour that researchers say may shed light on the origins of human feasting. The study, led by scientists from the University of Exeter, captured the apes on camera consuming African breadfruit in Cantanhez National Park.
The fruit tested had an alcohol content of up to 0.61% ABV, equivalent to a light beer. While not enough to cause intoxication, the chimpanzees consumed large quantities daily, potentially ingesting a fair amount of alcohol. The researchers noted that sharing the fermented fruit was not a common behaviour, suggesting it may have social significance.
“For humans, drinking alcohol leads to a release of dopamine and endorphins, and feelings of happiness and relaxation,” said Anna Bowland from the University of Exeter. “Sharing alcohol helps form and strengthen social bonds. Now we know wild chimpanzees are eating and sharing ethanolic fruits, the question is: could they be getting similar benefits?”
The footage showed chimpanzees of all ages and sexes sharing the fruit. On one occasion, two adult females, Chip and Até, ignored a larger piece of breadfruit in favour of a smaller fermented one. Two adult males, Mandjambé and Gary, approached ripe fruit with aggressive stances before eventually sharing it.
The study, published in Current Biology, asks whether feasting behaviour originates from a common ancestor. “We need to find out more about whether chimpanzees deliberately seek out ethanolic fruits and how they metabolise it,” said Dr Kimberley Hockings. “This behaviour could be the early evolutionary stages of feasting, suggesting the human tradition may have deep evolutionary roots.”
