The prevalence of drunk animals in the natural world is more significant than previously believed, which adds to human fascination with alcohol. A recent study published in Trends in Ecology & Evolution has shed light on the fact that many fruit-eating and nectar-sipping animals consume ethanol, a type of alcohol produced from fruit and grain sugars.
This discovery challenges the human-centric perspective that ethanol is solely a substance used by humans. Kimberley Hockings, a senior author and behavioral ecologist at the University of Exeter, emphasized that ethanol has a long history dating back to the late Cretaceous period when flower and fruit-bearing plants first emerged. As fruit falls and decays, yeasts in the air and on the fruit’s surface convert sugar into ethanol, giving off an odor similar to that of beer or wine.
In some cases, decaying fruit can produce ethanol levels exceeding 10 percent ABV, comparable to wine. However, most fruits typically contain 1 to 2 percent ABV, akin to kombucha or low-alcohol beers. Even this mild level of alcohol can have potent effects on birds or small mammals that consume alcoholic fruit, potentially leading to a deadly intoxication.
Matthew Carrigan, a professor of molecular ecology, warned that animals consuming ethanol face risks such as impaired judgment and coordination, making them easy targets for predators. In contrast to humans who pursue intoxication, animals seek out the calories in fruit but not the alcohol-induced buzz. They have developed genetic adaptations to metabolize ethanol without becoming intoxicated, enabling them to safely enjoy the sweet aroma of ripe fruit without risking intoxication.
Despite the assumption that animals actively avoid getting drunk, researchers are unsure if animals intentionally seek out intoxication. The growing recognition of sentience and intelligence in animals has reshaped our understanding of their behaviors. The idea of communal drinking among social animals suggests potential benefits, similar to the role of social imbibing in the early human societies that led to the formation of cities.
The study presented images of primates such as chimpanzees, spider monkeys, and Capuchin monkeys consuming fermented fruit, hinting at possible cognitive and social advantages of ethanol consumption. Anna Bowland, a behavioral ecologist at the University of Exeter, proposed that ethanol may activate the endorphin and dopamine systems, inducing feelings of relaxation that could have social benefits. However, further research is needed to determine if ethanol elicits physiological responses in the wild.
The implications of alcohol consumption in animals extend beyond individual behavior to possible effects on social dynamics and ecological interactions. This new perspective on drunk animals challenges the traditional view of human exceptionalism and highlights the diverse ways in which alcohol influences behavior in the natural world. Whether intentional or incidental, animal intoxication adds a fascinating layer to the study of animal behavior and evolution.
