Chimpanzees may have a penchant for alcohol, consuming amounts equivalent to two standard alcoholic drinks daily through fermented fruit, according to recent research.
The findings, stemming from studies conducted in Kibale National Park, Uganda, support the “drunken monkey hypothesis,” which suggests that primates are naturally drawn to alcohol and actively seek it out in their diets. Understanding animal behavior related to alcohol consumption can offer insights into the evolutionary history of human drinking habits.
Researchers from the University of California, Berkeley, and the University of Michigan discovered that the fermented fruits chimpanzees eat contain alcohol levels comparable to 14 grams of ethanol – the amount found in two standard alcoholic drinks. To confirm the extent of alcohol intake, researchers turned to an unconventional method: analyzing chimpanzee urine.
Collecting urine samples from wild chimpanzees presented logistical challenges. In August 2025, researchers devised a system using forked branches fitted with plastic bags to create shallow collection bowls. They strategically positioned these collectors under trees where chimpanzees were feeding, patiently waiting for the animals to urinate before moving to their next location. The team also collected samples from puddles on the forest floor.
“Staying clear of the spray zone” proved crucial during the collection process, according to researchers. The study, published in Science, provides further evidence of chimpanzees’ regular alcohol consumption. The research builds on previous observations of chimpanzees frequently feasting on fermented fruit in the wild, as reported by Popular Science.
As descendants of fruit-eating apes, humans may share this inherent tendency to consume alcohol, researchers suggest. The study highlights the potential evolutionary link between primate behavior and human alcohol consumption patterns.
