Scientists from the University of Exeter have recorded wild chimpanzees in Guinea-Bissau sharing alcohol-rich fruits, marking the first documented case of such behavior among great apes. This discovery may shed light on the deep evolutionary roots of human alcohol consumption and the social functions it serves.
Table of Contents:
- Chimpanzees in Cantanhez share fermented Okwabäume fruit
- Parallels between humans, chimpanzees and other species
- Deer, moose and fruit flies also affected by alcohol
- Evolutionary implications of alcohol consumption across species
Chimpanzees in Cantanhez share fermented Okwabäume fruit
Between 2020 and 2024, researchers led by Anna Bowland and Kimberley Hockings documented 10 distinct events in the Cantanhez National Park where chimpanzees consumed and shared fermented fruits from the Okwabaum. These pumpkin-like fruits, weighing up to 15 kilograms, can contain up to 0.61 percent alcohol.
The chimpanzees were seen eating the soft, fermented pulp and, in multiple instances, passing it to other members of the group. According to Bowland, this is “the first recorded evidence of great apes sharing alcohol-like food sources”. The findings suggest that alcohol sharing may play a role in strengthening social bonds, much like in human celebrations.
Parallels between humans, chimpanzees and other species
The study’s implications extend beyond chimpanzees. Insects, small mammals, and even deer have also been documented consuming alcohol-rich substances. Insects such as Oriental hornets can consume large quantities of alcohol without any apparent behavioral effects. These hornets metabolize alcohol efficiently, possibly offering insight into human alcohol dependency.
Similarly, the feather-tailed treeshrew in Malaysia regularly drinks fermented nectar with an alcohol content of 3.8 percent. Despite the high intake, the animals show no signs of intoxication. This has led researchers to hypothesize that certain species can digest alcohol purely as an energy source.
Deer, moose and fruit flies also affected by alcohol
Other animals, however, show visible signs of intoxication. White-tailed deer have been seen eating fermented apples and then displaying unsteady movements. In Scandinavia, moose are frequently found behaving erratically after consuming fermented fruit. One case in 2011 involved a moose that became so drunk it got stuck in a tree. In 2019, another broke into a kindergarten and had to be scared off by a teacher.
Insects like male fruit flies have also exhibited increased alcohol consumption after being rejected by females. Researchers from the University of California in San Francisco found that both alcohol and mating activate the brain’s reward system in flies, drawing a direct neurological parallel to humans.
Evolutionary implications of alcohol consumption across species
The findings from Guinea-Bissau complement earlier data showing wild chimpanzees in Guinea consuming up to three liters of fermented palm sap containing nearly 7 percent alcohol. These apes exhibited clear signs of inebriation before falling asleep.
According to the 2020 publication “Alcohol and Humans: A Long and Social Affair”, alcohol has influenced the evolution of numerous species, fostering symbiotic relationships between plants, microbes, insects, and mammals. Bowland and Hockings argue that alcohol may serve multiple roles in animal diets: as a medicinal agent, a calorie source, and a social lubricant.
Whether or not non-human animals consciously seek intoxication remains an open question. Yet the growing body of evidence points to alcohol as a natural and, at times, beneficial element in the diets of many species, including our own evolutionary ancestors.
Source: WELT