Chimpanzees in Guinea, West Africa drink naturally fermented palm wine from raffia palm trees, sometimes enough to exhibit "visible signs of inebriation," according to a new scientific study. From BBC News:
The chimps used drinking tools called leaf sponges – handfuls of leaves that they chew and crush into absorbent sponges, dip into the liquid and suck out the contents.
To work out the extent of the animals' indulging, the scientists measured the alcohol content of the wine in the containers and filmed the chimps' "drinking sessions".
The research team, led by Dr Kimberley Hockings from Oxford Brookes University and the Centre for Research in Anthropology in Portugal, worked out that the sap was about 3% alcohol by volume.
"Some individuals were estimated to have consumed about 85ml of alcohol," she said, "the equivalent to 8.5 UK units [approximately equal to a bottle of wine]".
"[They] displayed behavioural signs of inebriation, including falling asleep shortly after drinking.
Tools to tipple: ethanol ingestion by wild chimpanzees using leaf-sponges (Royal Society Open Science)