It’s a Party: Animals All Over the World Enjoy Booze

There are plenty of anecdotes about animals getting squiffy on fermented fruits in the wild, but we tend to think of these drunken episodes as rare and accidental. New research, which appears in Trends in Ecology & Evolution, challenges this assumption.

“We’re moving away from this anthropocentric view that ethanol is just something that humans use,” study co-author Kimberley Hockings says in a University of Exeter press release. “It’s much more abundant in the natural world than we previously thought, and most animals that eat sugary fruits are going to be exposed to some level of ethanol.”

So who’s drinking? Anecdotal evidence includes tales of elephants and baboons getting drunk on marula fruit in Botswana, a moose hopped up on fermented apples stuck in a tree in Sweden, and wild green monkeys in the Caribbean getting loopy on alcoholic fruit cocktails taken from tourists on St. Kitts.

“From an ecological perspective, it is not advantageous to be inebriated as you’re climbing around in the trees or surrounded by predators at night – that’s a recipe for not having your genes passed on,” says study co-author Matthew Carrigan. “It’s the opposite of humans who want to get intoxicated but don’t really want the calories – from the non-human perspective, the animals want the calories but not the inebriation.”

Besides the calories, ethanol could also have medicinal benefits. Fruit flies intentionally lay their eggs in alcohol-laden substances to protect their eggs from parasites. When persistent parasites, like wasps, manage to “parasitize” their hosts anyway, the fly larvae drink even more. Who wouldn’t?

We don’t know exactly why there’s so much drinking in the animal kingdom, only that it's everywhere and has been going on a long time. Ethanol entered the world about 100 million years ago, when flowering plants began producing fruits and nectar, which yeast could then ferment. Today it is present naturally in nearly every ecosystem on Earth, but especially so in low-latitude, humid tropical environments that can produce fruit – and therefore booze – year round. It’s always happy hour in the tropics.

Photo credit: Julia Casorso/University of Exister