Oct 04, 2025 22:00:00

Study reveals that wild chimpanzees consume the equivalent of one beer of alcohol per day

Humans are not the only species that drink alcohol: Previous studies have shown that wild monkeys

enjoy consuming alcohol , and that wild chimpanzees share fermented foods containing alcohol with their peers . A new study measured the alcohol concentration in fruits collected by wild chimpanzees and found that chimpanzees consume the equivalent of one beer per day.

Ethanol ingestion via frugivory in wild chimpanzees | Science Advances
https://www.science.org/doi/10.1126/sciadv.adw1665

Wild Chimps Consume The Equivalent of a Beer a Day, Study Finds : ScienceAlert
https://www.sciencealert.com/wild-chimps-consume-the-equivalent-of-a-beer-a-day-study-finds

Chimps consume equivalent of a beer a day in alcohol from fermented fruit | Science | The Guardian
https://www.theguardian.com/science/2025/sep/17/chimps-drink-beer-day-alcohol-fermented-fruit

The ripe fruits eaten by chimpanzees contain ethanol , a type of alcohol produced through natural fermentation. Alexei Marot, a doctoral student at the University of California, Berkeley, and his team measured the ethanol concentrations in fruits collected by chimpanzees from fallen fruit in national parks in Uganda and Côte d'Ivoire.

The ethanol concentration in the approximately 20 types of fruit eaten by chimpanzees was not particularly high, at around 0.3% on average, but since chimpanzees eat about 4.5 kg of fruit per day, it is estimated that their daily ethanol intake amounts to about 14 g.

'Chimpanzees eat 5 to 10 percent of their body weight in ripe fruit per day, so even low concentrations of alcohol mean a significant daily intake,' said Robert Dudley , a co-author of the study and professor of biology at the University of California, Berkeley.

This finding is consistent with the '

drunken monkey hypothesis,' proposed by Dudley more than a decade ago, which suggests that humans developed a preference for alcohol because our ancestors relied on ripe, fermenting fruit as a primary food source.

'For the first time, we have confirmed that our closest living relatives regularly consume physiologically significant amounts of alcohol,' said Maro. 'The drunken ape hypothesis is becoming increasingly plausible.'

It is unclear whether chimpanzees actively seek out fruits containing alcohol or whether they accidentally eat fruit containing alcohol. The research team plans to continue exploring the origins of human alcohol consumption through the topic of chimpanzee alcohol consumption.

'We can learn about ourselves through chimpanzees,' Malo said.