Overview
- Published in Biology Letters, the UC Berkeley–led study tested urine from Ngogo chimpanzees in Uganda’s Kibale National Park during an August 2025 fruit glut.
- Ethyl glucuronide was detected in 17 of 20 samples at 300 ng/ml sensitivity, and 10 of 11 tested exceeded the 500 ng/ml cutoff used in human screening.
- Researchers attribute exposure to naturally fermenting fruits such as African star apples, which contained roughly 0.09–0.4% ethanol by weight during sampling.
- Field teams used improvised, noninvasive collectors—plastic bags on forked branches, leaf splashes, and small puddles—to gather samples over 11 days.
- Findings align with prior intake estimates of about one to two human-equivalent drinks per day, though selective preference and behavioral effects remain unproven, with negatives skewing toward females and juveniles.