Wild chimps in Africa drink 1-2 alcoholic drinks daily

Wild chimpanzees in forests of Uganda and Ivory Coast ingest the equivalent of roughly one to two alcoholic drinks each day by eating fermented, ripe fruit, researchers at the University of California, Berkeley said after measuring ethanol in fruit collected at two long‑studied chimpanzee sites. The study, based on samples from Ngogo in Kibale National Park and Taï National Park, estimates wild chimps consume about 14 grams of pure ethanol per day through their normal fruit intake, an amount that becomes equivalent to more than two drinks when adjusted for chimpanzees smaller body mass.

The team measured ethanol concentrations in 20 to 21 fruit species the apes commonly eat and combined those figures with long‑term observations of how much fruit chimps consume. Average ethanol content of fruit pulp was about 0.3 percent by weight, and chimpanzees routinely eat roughly 4.5 kilograms of fruit a day, or about 5 to 10 percent of their body weight. Figs and several plumlike fruits were among those with the highest ethanol levels and are frequently consumed at both sites.

"Aleksey Maro," a graduate student and first author, said that across both sites males and females consumed about...