Explainer: How animals get ‘tipsy’ on fermented fruit

People are not the only ones who delight in acquiring a sense of excitement. According to a new study, a variety of species, including birds, lemurs, and monkeys, are also consuming naturally fermented fruit and nectar that contains ethanol, the same substance found in alcoholic drinks. This finding highlights how alcohol exposure may have comparable effects on animals as it does on people and even calls into question the evolutionary explanations for this phenomenon.

Animals and Ethanol: Not Just a Human Experience

New research is casting doubt on the long-held belief that ethanol is a human pleasure. Ethanol is found in many ecosystems, especially in fruits and nectar that ferment on their own. A leading researcher at the University of Exeter named Kimberley Hockings claims that ethanol is “much more abundant in the natural world than we previously thought.” As a result, modest ethanol levels are almost always present in animals that consume sweet fruits.

Primates Getting a “Natural High”

Primates displayed some of the most pronounced signs of purposeful ethanol consumption among the animals studied. For example, chimpanzees have been seen gathering sap with detectable ethanol concentrations from leaves using improvised “sponges.” Primates actively seek out these sources because of their special qualities; this behaviour is not purely coincidental. Ethanol may stimulate the endorphin and dopamine systems in these animals, resulting in relaxation and potential social advantages, according to the study’s main author Anna Bowland.

Preferences for Fermented Fruits

Surprisingly, animals in controlled environments showed a preference for foods with higher ethanol content. For example, the study discovered that diets with ethanol levels ranging from two to five percent alcohol by volume (ABV) were preferred by captive aye-ayes, or long-fingered lemurs. In Panama, wild fruit such as overripe palm fruits can contain up to 10.2% ABV, illustrating how some animals might be attracted to highly fermented foods naturally.

The Evolutionary Angle: Adaptation and Survival

What is the rationale behind animals’ consumption of ethanol, and is there any potential evolutionary advantage? According to the study, several animals have gradually acquired the capacity to effectively metabolise ethanol. Animals may be able to access more food sources that other species avoid thanks to this adaption. It is still unknown, though, if animals are purposefully ingesting the ethanol for its effects or just for the calories the fermenting fruits supply.

When Wildlife Behaves “Drunk”

Although uncommon, instances of animals acting strangely after eating fermented foods have been reported. After consuming fermented berries, certain species, such as cedar waxwings, have been known to have mid-air mishaps. These odd behaviours offer more proof that ethanol exposure occurs in the environment and that occasionally the effects are apparent.

Shifting Perspectives on Animal Ethanol Consumption

The results of this study challenge our presumptions about how alcohol affects animal behaviour. This study emphasises that ethanol use is a natural occurrence in the wild rather than being viewed as a completely human activity. Because of their developed metabolic systems, many animals may be consistently eating ethanol without experiencing any negative effects.

In summary, it appears that humans aren’t the only ones who can experience a tiny “natural high”! We might learn even more intriguing things about how and why wild animals interact with ethanol in their environments when further research is conducted.