As the holiday season approaches and many prepare for festive drinks with family and friends, a new study suggests that alcohol consumption among animals may not be as rare as previously believed.
Ecologists from the University of Exeter argue that ethanol, being naturally present in nearly all ecosystems, is likely consumed regularly by most fruit- and nectar-eating animals. While naturally fermented fruits typically contain only 1-2% alcohol by volume (ABV), concentrations as high as 10.3% ABV have been found in overripe palm fruit in Panama.
The researchers say that animals such as primates and treeshrews have evolved to efficiently metabolise ethanol. Senior author Matthew Carrigan noted that it’s not advantageous for animals to become inebriated while climbing trees or avoiding predators at night. Unlike humans, who seek intoxication without the calories, animals want the calories but not the inebriation.
The review explores potential benefits of ethanol consumption, such as providing calories or guiding animals to food sources through fermentation-related odours. Ethanol may also offer medicinal benefits; for instance, fruit flies deliberately lay their eggs in ethanol-containing substances to protect them from parasites.
It remains uncertain whether animals intentionally consume ethanol for ethanol’s sake, and further research is needed to explore its effects on animal physiology and evolution, the researchers say.
The paper, entitled “The evolutionary ecology of ethanol” was published recently in the Cell Press journal Trends in Ecology & Evolution.
