Monkey-like primates such as aye-ayes and slow lorises enjoy alcohol and even choose the highest concentration of alcohol available to them, according to a new study conducted by Dartmouth scientists.
Researchers at Dartmouth College in New Hampshire put the two species of primates to the test, giving each a selection of beverages with varying levels of alcohol. Like many of their human counterparts, the primates were found to prefer the stiffest booze available and, in some cases, devoured it like college students on New Year’s Eve.
The study, conducted by Samuel Gochman, Michael Brown, and Nathaniel Dominy, purported to observe whether or not primates were more naturally inclined toward heavily fermented forms of nectar resembling human booze when given a choice of beverages in simulated living conditions.
To put this booze study to the test, the researchers conducted an experiment with Dharma, a slow loris, and two aye-ayes named Morticia and Merlin at the Duke Lemur Center in Durham, North Carolina. Both species are considered monkey-like primates. Aye-aye lemurs are native to Madagascar, while the slow loris thrives in the jungles of southeastern Asia, where booze usually takes the form of fermented tree fruit.
In the study, the researchers placed drink receptacles in slots cut into a round table with lids that left a hole just big enough for the primates to insert their fingers to taste test the drinks. This measure was designed to simulate the nectar gathering process the two primate species go through in their native habitats.
The boozed nectar substitutes ranged from 1 to 4 percent in alcohol content, with tap water as a control. In all cases, even after the researchers changed the order in which the drinks were arranged, the primates preferred the strongest booze.
The researchers reported in the Royal Society Open Science that Dharma not only preferred the booze, but had a “relative aversion to tap water.” The aye-ayes, Merlin and Morticia, reportedly went straight for the most alcoholic option and continued probing the booze receptacles for more even after they had emptied them of their contents.
“Compulsive digital probing for residual traces of alcohol suggests a strong attraction or craving,” they suggest.
One might speculate from this study that primates enjoy booze in their natural habitat because caloric value rises as nectar ferments, providing them with valuable energy. However, some experts, such as Matthew Carrigan of Santa Fe College in Florida, are surprised by the results of this primate study.
“It’s a challenge to use those calories without getting inebriated,” said Carrigan to USA Today. “If you are climbing around in the trees, 40 to 50 feet off the ground, perhaps at night and surrounded by predators, would you want to be drunk?”
According to the Guardian, Gochman, a Dartmouth biology student who co-authored the study, somewhat answers Carrigan’s question in the published paper.
“No signs of inebriation were observed,” said Gochman.
This Dartmouth College study is not the first and only of its kind to measure primate booze consumption. Another study, also published in Royal Society Open Science, observed chimpanzees in Guinea who used chewed-up leaves as sponges to soak up and ingest fermented sap from a tree species that native villagers use to make “palm wine.” This study, which was conducted over a 17-year period, found these primates to have a strong inclination for booze.
“Some individuals were estimated to have consumed about 85ml of alcohol,” said Oxford Brookes University researcher Kimberly Hockings, according to BBC News.
This is about the equivalent of a full bottle of wine.
If humans and primates come from a common ancestor, as evolutionary theory implies, these studies might shed some important light on why humans enjoy booze, even to the point of abuse.
[Photo by Ed Wray/Getty Images]