Chimpanzees in the wild get drunk on palm tree wine. Past studies have showed that humans’ closest primate cousins have an understanding of language and the ability to cook. Now a group of researchers has discovered that they also share a taste for alcohol. Scientists led by Dr Kimberley Hockings from Oxford Brookes University studied chimpanzees living near the village of Bossou in Guinea for 17 years (1995-2012).
Chimps have developed tools for this
For the first time, scientists have officially confirmed that wild chimps habitually drink alcohol. Findings of the study were published in the Royal Society Open Science. The study recorded chimpanzees using leaves to drink fermented palm sap. Some of them even showed “visible signs of inebriation” after drinking alcohol.
Villagers in the Bossou area tap raffia palm trees to harvest “palm wine” with plastic containers placed near the crowns of the trees. Local people leave the containers alone for most of the day, collecting palm wine in the morning and evening. Chimps use “leaf sponges” to drink alcohol. They scrunch up leaves in their mouths, crushing into absorbent sponges. Then they dip leaf sponges into plastic containers placed by villagers, and suck out the content from leafy tools in their mouths.
Chimpanzees consume strong alcohol
Researchers found that the chimps consumed fermented sap in large quantities. They also filmed the chimps’ “drinking sessions” and measured the alcohol content of the palm wine in containers. They found that the fermented sap’s alcoholic content varied between 3.1% and 6.9%, almost equivalent to a strong beer.
After drinking, chimpanzees showed signs of inebriation. On one particular occasion, an adult male chimp was extremely restless. While others were settling into their nests, he spent an extra hour moving in an agitated manner from tree to tree, Hockings told BBC News. Scientists observed a total of 51 instances of drinking sessions. Males accounted for 34 of the 51 instances
Individual chimpanzees either co-drank or one chimp monopolized the container while others waited for their turn.