Drunk animals are much more common than previously thought, scientists say

drink alcohol According to a new scientific paper, which claims that ethanol consumption is widespread in the animal world, it may be much less unique to humans than previously thought.

While the stories of the wild animals drunken behavior after consuming fermented fruit often make headlinesthis behavior is mostly considered rare and random.

However, ecologists have challenged this “anthropocentric” view in a new review of scientific papers published in Trends in ecology and evolution magazine.

They argue that because ethanol is naturally present in almost every ecosystem, it is likely regularly consumed by most fruit- and nectar-eating animals.

From chimpanzees to shrews, the researchers found a “diverse group” of species that scientists previously noted had adapted to ethanol in their diet.

“We’re moving away from this anthropocentric view that ethanol is just something people use,” said Dr Kimberley Hawkings, a behavioral ecologist at the University of Exeter. “It’s much more abundant in nature than we previously thought, and most animals that eat sugary fruit will be exposed to some amount of ethanol.”

Ethanol first appeared in large quantities about 100 million years ago, when flowering plants began to produce sweet nectar and fruit that yeast could ferment. Naturally fermented fruit usually reaches only 1-2 percent alcohol by volume (ABV), but overripe palm fruits have been found to contain concentrations of up to 10.2 percent ABV.

Although animals already had genes capable of metabolizing ethanol before yeast began to produce it, there is evidence that evolution has since fine-tuned this ability for fruit- and nectar-eating mammals and birds, the scientists said.

“It’s not ecologically beneficial to be drunk when you’re climbing trees or around predators at night — that’s a recipe for not passing on your genes,” said Matthew Kerrigan, a molecular ecologist at the College of Central Florida.

“It’s the opposite of people who want to be high but don’t really want the calories – from a non-human perspective, animals want the calories but not the high.”

However, researchers say that consuming ethanol may have several benefits for wildlife. Besides being a source of calories, ethanol may also have medicinal benefits, scientists say.

They indicated that fruit flies deliberately deposit their eggs in substances containing ethanol, which protects their eggs from parasites, and that fruit fly larvae increase ethanol consumption when they are parasitized by wasps.

“On the cognitive side, it has been suggested that ethanol may trigger the endorphin and dopamine system, leading to a feeling of relaxation that may have social benefits,” said Anna Bowland, a behavioral ecologist at the University of Exeter.

“To test this, we really need to know if ethanol causes a physiological response in nature.”

However, some cases in insects indicate a social link with ethanol consumption. One 2012 study found that male fruit flies increased their numbers drinking alcohol after being rejected by a mate, while females of closely related species appeared to be less selective in their mate choice after drinking ethanol.

And in another theory first proposed in 2014, known as the “drunken monkey” hypothesis, Berkeley biologist Professor Robert Dudley argued that humans’ taste for alcohol began millions of years ago, when primates discovered that the smell of ethanol prompted them to ripen, fermenting and nutritious fruit.

Until he was able to provide evidence as to whether apes are actually human-like was looking for fermented fruits or digested alcohol, a follow-up study in 2022 of black-armed spider monkeys in Panama found that these primates regularly foraged for the fruits of the jobo tree which were ripe enough to contain alcohol.