Overview
- A Science Advances study measured ethanol in fruits eaten by chimpanzees, finding average concentrations near 0.3 percent across 20 species.
- Based on typical fruit consumption, wild chimpanzees ingest about 14 grams of pure ethanol per day, roughly one U.S. standard drink and nearly two when adjusted for body weight.
- Researchers sampled fallen fruits at Taï National Park in Côte d'Ivoire and Kibale National Park in Uganda, with consumed fruits showing higher ethanol levels than the local average.
- The team reports no obvious signs of intoxication because alcohol intake is spread throughout the day, and a chimp would need to overfill its stomach to feel tipsy from fruit alone.
- Findings bolster the Drunken-Monkey Hypothesis, while questions remain about active selection for higher-ethanol fruits, which the team is probing next by analyzing urinary metabolites.