Sometimes being a wildlife biologist means filming a lemur picking its nose. Isn’t science glamorous? For the first time ever, footage of an aye-aye – a species of endangered lemur from Madagascar that looks a bit like the koala’s meth-addicted cousin – was recorded showing the animal slipping a spindly middle finger into its nose and gobbling up the slimy rewards (be warned: this cannot be unseen).

Filmed by University of Bern biologist Anne-Claire Fabre, the culprit in the clip is an aye-aye named Kali who lives at the Duke Lemur Center in North Carolina and now goes down in history as the first of her species busted with a finger in her schnoz. The uncouth act became even more fascinating when researchers investigating the behaviour dug a little deeper.

“We were in for an even bigger surprise when we used CT scanning to see how the nose picking works internally,” explained Roberto Portela Miguez, a co-author of the study published in the Journal of Zoology. “The scan was mind-blowing. We were shocked from the reconstruction that the aye-aye's finger could reach through its nose almost to the back of its throat.”

This CT-scan reconstruction shows an aye-aye picking its nose. Credit: Renaud Boistel

That’s some next-level nose mining. But if any species can do it, it’s the aye-aye. These lemurs have a specially adapted, eight-centimetre-long middle finger that puts ET’s healing digit to shame. The aye-aye uses its weird finger to hunt for wood-boring insect larvae hiding out under the bark of trees.

Foraging happens at night and usually involves the lemur rapidly tapping on branches with its creepily long finger (as many as seven times a second) and listening for evidence of any tunnels or voids in the wood. Once it’s made a mental map of the inner workings of a branch, the aye-aye will bite off chunks of wood in strategic spots and use its finger like a probe to fish out any tasty grubs.

It seems their food-finding fingers may also be useful when foraging inside their own heads. The researchers do note, however, that Kali is a captive animal, which may play a role in her behaviour. Observations of wild lemurs picking their noses would help confirm that this record is not just an isolated incident (any keen researchers up for the job?).

Nose picking has been recorded in 12 primate species (including humans), but the reasons for the behavior are not fully understood. Relieving a blockage, gaining nutrition and supporting the immune system have all been suggested as possible explanations, but none of these theories have been conclusively proven.

Perhaps Kali just did it for the fame.

Header image: nomis-simon