The Alcoholics of the Animal World

You may have seen the story earlier this week of the drunken Swedish moose (or elk, as they call the antlered behemoth in Sweden) that got stuck in a tree. “I thought at first that someone was having a laugh. Then I went over to take a look and spotted an elk stuck in an apple tree with only one leg left on the ground,” Per Johansson, who spotted the inebriated mammal in the garden next door to his house in Särö, told The Local. The moose likely got drunk eating apples fermenting on the ground and got stuck in the tree trying to get fresh fruit. “Drunken elk are common in Sweden during the autumn season when there are plenty of apples lying around on the ground and hanging from branches in Swedish gardens,” The Local states.

Moose aren’t the only non-human animals with a taste for alcohol, though.

The pen-tailed treeshrew of Malaysia gets credit for having the world’s highest alcohol tolerance. Seven species of animals, including the treeshrew and the slow loris, feed on fermented nectar from the flower buds of the bertam palm plant. But though the treeshrew quaffs this brew all day long, it doesn’t get drunk, scientists found in a 2008 PNAS study. “They seem to have developed some type of mechanism to deal with that high level of alcohol and not get drunk,” University of Western Ontario microbiologist, and study co-author, Marc-André Lachance told LiveScience. “The amount of alcohol we’re talking about is huge—it’s several times the legal limit in most countries.”

Fruit bats also appear to tolerate the effects of fermentation on fruit better than the Swedish moose did. In a 2010 PLoS ONE study, scientists fed wild-caught fruit bats sugar water laced with alcohol and sent them through a maze. Though many of the bats would have gotten a FUI (flying under the influence) citation, they had no more trouble navigating than did bats given sugar water alone. The researchers think that being able to tolerate alcohol lets the bats have access to a food source—fruit—for a longer period than only when it’s ripe.

Rhesus macaques, however, are more like humans than treeshrews, according to a 2006 Methods study in which the monkeys were given access to an alcoholic drink in a series of experiments. “It was not unusual to see some of the monkeys stumble and fall, sway, and vomit,” study co-author Scott Chen, of the National Institutes of Health Animal Center, told Discovery News. “In a few of our heavy drinkers, they would drink until they fell asleep.” The macaques frequently drank until their blood reached the .08 level that would disqualify them from driving a car in most states. And when the researchers looked at patterns of drinking, macaques that lived alone tended to drink the most. In addition, they drank more at the end of the day, like humans after a long day of work.

But stories of drunk elephants on the African savannah are likely just stories, according to a 2006 study in Physiological and Biochemical Zoology. Local lore says that elephants get intoxicated from the fermented fruit of the marula tree. Elephants do have a taste for alcohol, but when scientists sat down to look at the claim, they found several problems. First, the elephants don’t eat the rotten fruit off the ground. They eat the fresh fruit right off the tree. Second, the fresh fruit doesn’t spend enough time in the elephant to ferment and produce alcohol there. And, third, even if the elephant did eat the rotten fruit, the animal would have to eat 1,400 pieces of exceptionally fermented fruit to get drunk.

The study probably won’t change the widespread belief in inebriated pachyderms, though. As the study’s lead author, Steve Morris of the University of Bristol, told National Geographic News, “People just want to believe in drunken elephants.”

Sarah Zielinski | | READ MORE

Sarah Zielinski is an award-winning science writer and editor. She is a contributing writer in science for Smithsonian.com and blogs at Wild Things, which appears on Science News.