Aye-aye! Image: David Haring

Humans may be more closely related to great apes, but according to science, our true spirit animals are aye-ayes. These Gollum-eyed lemurs like to skulk about in the forest getting liquored until the sun comes up. Wow, same!


Alcohol is found naturally in fermented nectars, honeys, and fruits, but the enjoyment of this liver-destroying toxin is seen as a uniquely human trait. This view, however, has recently come under fire—not only have field biologists observed chimps swilling naturally fermented palm wine, genetic studies suggest that the basis for alcohol tolerance (an enzyme called alcohol dehydrogenase) may be widespread among primates.

Which begs an important question: do our arboreal ancestors also imbibe crunk juice for kicks?

The slow loris. Image: David Haring

In the first controlled study to test that hypothesis, Dartmouth scientists turned to two likely alcoholics, ayes-ayes and the slow loris. Over the course of fifteen days in the case of aye-ayes and five days in the case of the slow loris, the animals were offered sugary solutions with alcohol concentrations varying from zero to five percent. They found that aye-ayes could not only discriminate between the different concentrations of alcohol, they preferred their soda with as much booze as possible. While the slow loris had similar feeding patterns, the trials were too few to yield statistically significant results.


Another trait aye-ayes share with humans: when their bottle runs dry, they continue to poke at it sadly, suggesting they want more. The researchers suspect that a preference for alcohol offers an evolutionary advantage, given that it’s a source of calories otherwise avoided. A likely excuse.

Correction 6/20/16: A previous version of this article incorrectly referred to aye-ayes as monkeys, they are in fact prosimians. We apologize for the error.

[Royal Society Open Science]