In the Cantanhez national park in Guinea-Bissau, wild chimpanzees have been observed sharing fruit containing alcohol.

The fruit, known as African breadfruit, was found to have an alcohol content of up to 0.61% ABV. Researchers used motion-activated cameras to film the chimpanzees on 10 occasions, showing them eating and sharing the fermented fruit.

The behavior was observed among all ages and sexes, with some individuals ignoring larger, non-fermented pieces in favor of smaller, fermented ones.

The chimpanzees were seen consuming large quantities of the fruit, potentially ingesting a significant amount of alcohol.

However, the researchers note that the alcohol level is relatively low and unlikely to cause intoxication.

The sharing behavior may be important for forming and strengthening social bonds among the chimpanzees.

This observation has led to questions about whether humans' tradition of feasting and bonding over alcohol may have its origins in a shared common ancestor with chimpanzees.

Further research is needed to determine whether the chimpanzees deliberately seek out ethanolic fruits and how they metabolize it.