Johnson: Two primates show affinity for alcohol

Images of staggering monkeys and swaying elephants are nothing new in pop culture and, for decades, depictions of drunken animals have worked their way into entertainment.

Human opinions are mixed — some want nothing to do with it, others enjoy it — in the animal world, however, human contrived depictions aside, there has long been evidence that alcohol consumption not only happens in the wild, but for some species is downright habitual.

Although some monkeys, elephants and other animals living near humans have been reported to stumble upon and develop a taste for alcohol produced by humans, the alcohol consumed by wild critters is generally not the same kind.

To the contrary, the majority of wild animals known to imbibe are doing so with the help of fermented berries, fruits and plants they encounter in natural habitats.

Bats have been documented with blood alcohol levels as high as .3 percent — well above the legal limit — from consuming fermented fruits, though they seem to maintain their coordination thanks to echolocation.

Bohemian waxwing birds are also been known to like berries that ferment on the branch in cool temperatures and while most handle things fairly well, it’s not uncommon for some of them to become so intoxicated that, unlike bats, they crash when attempting to fly.

Even bees sometimes indulge on fermented nectar, becoming so drunk they often lose their way back to the hive.

The list of species that have been identified as alcohol consumers is actually fairly long, however this week a newcomer to the list was announced and the affinity for alcohol these fellows have may actually help explain the foundation of human alcohol consumption.

Operating on growing knowledge that fermented food and alcohol are prevalent in the diets of primates in the wild, a team of researchers from Dartmouth College studied two primates that rarely make the news — the Southeast Asian aye-aye and slow loris.

Though it was known that plant nectars the two primates rely on do contain alcohol, researchers were looking to find out if the critters chose that nectar because of the alcohol it contains, or merely consumed it as a consequence of dependence on the plant as a food source.

Using aye-ayes and slow lorises that were kept in captivity and as a result, had minimal exposure to fermented foods in their diets, the researchers presented them with a choice between nectar containing differing levels of alcohol simulated to mimic what they would find in their wild habitat.

Consistently, the primates turned their noses up at offerings of tap water and instead were drawn to the nectar with the highest alcohol content, though researchers did note they didn’t show signs of intoxication regardless of how much they consumed.

Though not drunk, they just showed a strong liking for the highest alcohol content available, with some of the aye-ayes — known for a characteristic-probing finger they use in foraging — even scraped and probed the bottoms of empty containers searching for more.

An apparently instinctual affinity for alcohol, researchers theorize, is something aye-ayes and slow lorises share with their fellow primates, to include the great apes and humans, and it’s an affinity they believe long pre-dates humans discovering how to intentionally make alcohol.

This taste for alcohol, they conclude, has been long overlooked in anthropological dietary studies that have failed to measure the levels of alcohol — capable of increasing caloric intake and a critical survival staple — consumed by primitive humans and wild creatures.

In an era where, at least for people, calories are easier to get, evolving to understand alcohol's downsides, does, however, seem to be almost exclusively human.

Sharna Johnson is a writer who is always searching for ponies. You can reach her at:

insearchofponies

@gmail.com