Chimpanzee pee reveals how our primate cousins are getting drunk on fermented fruit

"Specifically, they consume alcohol inside fermented fruits, from figs to star apples to local stone fruits. As these fruits ripen, they produce sugars, which combine with yeast to produce ethanol. While the amount of ethanol in an individual piece of fruit is very small, chimps are voracious, with some eating about 4.5 kilograms of fruit a day."

"A new analysis of chimpanzees' pee confirms that the apes ingest enough alcohol to show up on field tests of their urine. The finding could shed light on how the psychoactive substance affects the animals' behavior."

"Maro and his team followed a group of chimps at Ngogo, a research site within Uganda's Kibale National Park. They collected the apes' urine and identified the presence of alcohol in the samples on-site with dipstick assays that are typically used to test humans for alcohol consumption."

Chimpanzees regularly consume alcohol by eating fermented fruits such as figs, star apples, and stone fruits. As these fruits ripen, their sugars ferment with yeast to produce ethanol. Individual chimps eat approximately 4.5 kilograms of fruit daily, potentially ingesting the equivalent of more than two standard alcoholic drinks when adjusted for body weight. Researchers at UC Berkeley collected urine samples from chimpanzees at Ngogo in Uganda's Kibale National Park and used dipstick assays to confirm the presence of alcohol in their systems. This finding provides the first direct evidence of alcohol consumption in wild chimpanzees and opens investigation into how this psychoactive substance influences their behavior and ecological interactions.

Read at www.scientificamerican.com