A study by the California State University Northridge (CSUN) proves that monkeys consume fruits containing alcohol. The scientists were able to prove that black-handed spider monkeys in Panama consume overripe fruits that contain up to two percent alcohol - and also metabolise it.
"For the first time, we have been able to show beyond doubt that wild primates preferentially consume fruits containing alcohol without human intervention," said Christina Campbell of CSUN. "More research is needed, but it looks like the human propensity to consume alcohol stems from a deep-rooted primate affinity for naturally occurring alcohol in ripe fruit."
University of Berkeley biologist Robert Dudley had already hypothesised that monkeys' attraction to the smell and taste of alcohol was an evolutionary trait. It enables them to find ripe, energy-giving fruit before other animals. Before the CSUN study, however, he could not back up his assumption with data.
"There is alcohol in the food that monkeys eat, because they eat a lot of fruit. This alcohol is actually metabolised by them. The study proves that secondary metabolites like ethyl glucuronide and ethyl sulphate are excreted in the urine," Dudley commented on the result, "but what we don't know yet is how much of it they ingest and what effect it has on their behaviour and physiology."
Christina Campbell explains the spider monkeys' behaviour this way: "They prefer fruits containing alcohol probably because of the amount of calories. Fermented fruits contain more of them than unfermented ones, and higher calories mean more energy." This need for caloric intake from fruit may also have influenced humans' decision on which fruits to eat, Campbell said. "Human ancestors may also have preferred to consume fruit containing alcohol because it contains more calories," she said. "The psychoactive and hedonistic effects of alcohol may also lead to increased consumption and therefore higher calorie intake."
(uka / Source: decanter.com et al - Photo: Wikipedia / Brian Gatwicke)