Ever wonder if chimps actually drink alcohol like we do? Turns out, yeah, they do—well, sort of. Chimpanzees naturally get a small dose of alcohol every day by eating fermented fruit. No, they’re not sipping wine or beer, but the amount of ethanol in their wild diet adds up to about two, maybe two and a half, human drinks each day.
Their alcohol comes from ripe fruits that ferment right on the trees. That’s pretty common in the forests where chimps hang out.
Since chimps are our close primate relatives, their habit of eating boozy fruit kind of hints at a shared history between us and them when it comes to alcohol.
Even though chimps eat these fruits all the time, they almost never look drunk or act out of it. It makes you wonder—how do their bodies handle alcohol, and does it play any part in their social lives or help them survive?
If you’re curious about how chimps and other primates deal with alcohol, stick around.
How Chimpanzees Ingest Alcohol in the Wild
You might find it surprising, but wild chimpanzees get natural alcohol in their diet almost every day. They eat a lot of fruit, and some of it is so ripe or fermenting that it contains ethanol.
This natural alcohol mostly comes from certain fruit species found in places like Uganda’s Kibale National Park and Ivory Coast’s Taï National Park.
Fermented Fruit and Natural Ethanol
Chimps don’t really know they’re drinking alcohol—they just love fruit, especially when it’s super ripe. Fermentation happens when yeast breaks down the sugars in fruit, turning them into ethanol. It all takes place right there in the wild as the fruit ripens or falls to the ground.
You’ll often see chimps munching on fruit that’s already fermenting. They get small, steady doses of natural alcohol this way. It’s not enough to make them tipsy, but it’s definitely a regular part of their diet.
Fruit-eating animals like chimps deal with this kind of ethanol all the time in tropical forests.
Key Fruit Species in the Chimpanzee Diet
Some fruit species play a huge role in how much ethanol chimps take in. Figs are a favorite, along with fruits from trees like Parinari excelsa. These trees drop sweet, ripe fruit that ferments naturally on the ground.
In Kibale and Taï National Parks, these fruits make up a big chunk of what chimps eat. Since chimps can eat 5 to 10 percent of their body weight in fruit every day, even a tiny bit of alcohol in each fruit adds up.
So, your wild chimp neighbors might actually be getting the equivalent of a couple drinks just from fruit.
Alcohol Content in Ripe and Fermenting Fruits
The ethanol level in fruit is usually low—about 0.3 percent on average—but it goes up as fruit gets riper or starts to ferment.
Even though the amount per fruit is small, chimps eat so much that they can take in up to 14 grams of alcohol each day. For us, that’s kind of like drinking two or three alcoholic drinks.
Chimps don’t gulp it all at once, though. They eat fruit throughout the day, which keeps them from getting drunk.
Some researchers think this steady, natural alcohol intake might even help chimps get along better during group activities after a big fruit feast.
Research Insights and Evolutionary Significance
Chimpanzees eat fermented fruit with alcohol in it all the time. Scientists have measured how much alcohol chimps actually get, looked at how it affects them, and even wondered if our own love of alcohol traces back to these primate habits.
Measuring Alcohol Intake in Chimpanzees
Aleksey Maro and his team studied chimps in Uganda and Côte d’Ivoire. They checked out over 500 fruit samples and watched how long chimps spent eating each fruit.
By putting this data together, they figured chimpanzees eat about the same as 2 to 2.5 human drinks daily.
Chimps weigh less than we do, so 14 to 15 grams of alcohol is actually a strong dose for them. Nathaniel Dominy, an evolutionary biologist, found this pretty convincing. On the other hand, Matthew Carrigan pointed out that the study only tracked eating time, not the exact amount of fruit eaten.
If you want the details, you can check out their study in Science Advances. It’s a clever way to estimate alcohol intake without bothering wild chimps.
Chimpanzee Behavior and Alcohol Effects
Chimps seem to like fruit with higher alcohol levels. In Uganda, they go for certain figs that are boozier. Over in Côte d’Ivoire, they prefer plums with more alcohol. Maybe alcohol signals that the fruit is sweeter or has more calories—makes sense, right?
Even when they eat these fruits, chimps rarely get drunk. Their bodies break down alcohol quickly, thanks to special enzymes. Humans and gorillas have these too.
But sometimes, chimps find a fruit they really love and eat a lot at once—kind of like us with junk food. In rare moments, chimps have even been spotted drinking fermented palm sap and showing mild signs of intoxication.
Still, wild chimps almost never get truly drunk. Staying sober helps them climb trees and, honestly, survive another day.
The Drunken Monkey Hypothesis
Robert Dudley came up with the “Drunken Monkey” hypothesis. He thinks humans picked up a taste for alcohol from our primate ancestors, like chimps.
Early primates probably munched on fermented fruit pretty often. That set the stage for alcohol tolerance and a preference for booze.
Aleksey Maro’s team just found more evidence for this idea. Chimps drink the equivalent of two or more drinks a day—honestly, that’s wild to think about.
This kind of behavior goes way back in our evolutionary tree. Maybe that’s why so many people today find alcohol so tempting.
It’s fascinating to see how our genetics and evolution tie us to chimps. Your love for a drink might actually go back millions of years.
For more on this, you can check out how researchers connect chimp alcohol intake to human behavior in scientific discussions.
