Wild chimpanzees enjoying opportunistic booze-ups on palm wine have helped shed light on a theory about evolution, scientists said on Wednesday.
Chimps in the west African country of Guinea discovered a free treat in raffia palms tapped by local people to extract a sweet, milky sap which then ferments into an alcoholic drink.
The apes scrunched up leaves in their mouths, moulding them into spongy pads that they then dipped into the sap-gathering container, which villagers attach to the tree near its crown.
Tests showed that the beverage's alcoholic content varied from 3.1 percent to a whopping 6.9 percent, the equivalent of strong beer.
Some of the chimps went a little, well, ape.
"(They) consumed significant quantities of ethanol (alcohol) and displayed behavioural signs of inebriation," the paper said soberly.
"Researchers rarely collected detailed behavioural data before versus after exposure to ethanol, but some drinkers rested directly after imbibing fermented sap."
|Let's just hold each other up|
But the Bossou chimps, observed over 17 years, are the first to provide serious data about how much alcohol can be knocked back in the wild, and when.No word on whether they had sex after drinking. So we can't accuse them of drunken orgies. Yet.
Sometimes, just a single chimp would go to the top of the palm, the researchers found. But on occasions, there would be "drinking sessions" when several chums would gather in the crown of the tree.
"Individuals either co-drank, with drinkers alternating dips of their leaf-sponges into the fermented palm sap, or one individual monopolised the container, whereas others waited their turn."