Chimpanzees Ingest Everyday Ethanol Comparable to a Beer from Ripe Fruit

Studies of apes in their natural habitat show they consume the ethanol content of a small beer each day through their diet of fermented fruit.

Findings from African National Parks

Researchers measured ethanol levels in fallen fruit eaten by chimpanzees in Kibale National Park and Taï National Park.

While individual fruits had under 0.5% ethanol, the chimps’ daily intake increased as they devoured large quantities of fermented fruit flesh.

Fig fruits were a preferred choice among the apes, containing some of the highest alcohol levels observed.

Daily Alcohol Intake Equivalent to a Beer

According to scientific analysis, male and female chimpanzees consume approximately 14 grams of pure ethanol per day.

This dosage is equal to a typical alcoholic beverage.

“The apes consume 5 to 10% of their body weight in fermented fruit each day, so even low concentrations result in a high daily total of ethanol,” explained one scientist.

Historical Connection to Primate Alcohol Consumption

This behavior aligns with the “drunken monkey” theory, which proposes that modern preference to alcohol may have origins in our primate ancestors.

The attraction for high-calorie ripe fruit may have influenced a biological tendency toward ethanol intake.

Not the First Examples of Animal Drinking

Earlier studies have documented apes practicing regular drinking, with some starting as in the morning.

Additional animals also drink alcohol in the wild, including slow lorises that prefer strong fruit when accessible.

No Signs of Drunkenness

Even with eating up to 4.5kg of fermented fruit per day, the apes display no obvious effects of intoxication.

Researchers suggest that to feel the full effects of alcohol, the chimpanzees would need to consume an excessive amount fruit—enough to make them bloated.

Context with People’s Alcohol Guidelines

Health organizations recommend that people limit alcohol consumption to reduce potential harm.

Research show that there is no completely safe amount of ethanol consumption for humans.