Wild Chimpanzees Observed Sharing Alcoholic Fruits for the First Time

In a groundbreaking observation, researchers have documented wild chimpanzees engaging in the sharing of fruits containing alcohol. This behavior was recorded by a primarily British research team in the Cantanhez National Park located in Guinea-Bissau, West Africa. The study highlights a potential parallel between chimpanzee and human social drinking behaviors.

The team, led by researchers from the University of Exeter, found that the chimpanzees were consuming the fermented, pumpkin-shaped fruits of the Okwaba tree (Treculia africana), also known as the African breadfruit. These large fruits can weigh up to 30 kilograms and fall to the ground when they ripen. Remarkably, 24 out of the 28 fruits examined were found to contain alcohol levels reaching up to 0.61 percent.

Using camera traps, the researchers recorded a total of 70 instances of chimpanzees consuming these alcoholic fruits. In 9 out of 10 instances where the primates shared the food, the fruits were confirmed to be alcoholic. Both male and female chimpanzees of various ages participated in this sharing behavior. This marks the first documented evidence of non-human primates sharing food that contains alcohol, as detailed in the journal Current Biology.

While the reasons behind this sharing behavior remain unclear, the findings suggest a possible evolutionary link in the consumption of alcohol between humans and chimpanzees. The study raises intriguing questions about the social dynamics of these primates, particularly in relation to alcohol consumption.

Researcher Anna Bowland explained that alcohol consumption among humans is associated with the release of dopamine and endorphins, which elicit feelings of happiness and relaxation. Furthermore, sharing alcoholic beverages often plays a role in strengthening social bonds during communal activities. The researchers are now exploring whether similar effects occur in chimpanzees, proposing that this might represent an early form of social celebration.

One significant question posed by the study is whether the low levels of alcohol in the fruits are sufficient to induce a state of inebriation in the chimpanzees. Previous research from neighboring Guinea suggested that wild chimpanzees do indulge in alcoholic beverages, sometimes consuming large quantities. This earlier study indicated that chimpanzees could drink up to three liters of fermented palm sap, which has an alcohol content of up to 6.9 percent, and exhibited signs of intoxication thereafter.

Observations of both genders and various age groups of chimpanzees participating in these behaviors were reported, though only about half of the total observed animals were involved in the drinking. In captivity, alcohol consumption among primates has also been documented, further emphasizing the complexity of their interactions with alcoholic substances.

This remarkable study sheds light on the social behaviors of wild chimpanzees and opens new avenues for understanding the evolutionary roots of alcohol consumption and social bonding in primates. As researchers continue to explore these dynamics, it could reshape our understanding of primate behavior and its implications for human evolution.