Nose-poking primates help scientists understand the evolution and possible functional role of behavior in humans.
For the first time, researchers have recorded the aye-aye – a long-toed lemur – inserting its longest finger into its nostrils and then licking its finger clean.
So far, 12 other primate species, including humans, have been documented picking their noses and eating the mucus.
The scientists said their findings, published in the Journal of Zoology, could shed light on the evolution of this behavior and determine whether it has a functional role.
Lead author Anne-Claire Fabre, an associate scientist at the Natural History Museum in London, said: “There is very little evidence as to why we, and other animals, choose noses.
“Almost all the articles you can find were written as jokes. Among the serious studies, there are some in the field of psychology, but for biology, there is almost nothing.
“One study shows picking your nose can spread bacteria such as staph, while another shows people who eat their own snot have less tooth decay.”
The aye-aye, the largest nocturnal primate in the world, belongs to a category of species known as strepsirrhine primates and is native to Madagascar.
It has rodent teeth and a specialized long, thin middle finger.
The fingers of the aye-aye are used to locate food inside the wood by tapping on it, then extracting small larvae. The researchers also noticed that the lemur uses its longest finger to pick its nose.
Ms Fabre said: “It was impossible not to notice this aye-aye picking his nose.
“It wasn’t just a one-off behavior, but something he was fully engaged in, inserting his extremely long finger for a surprisingly long length into his nose, then sampling everything he dug up as he licked his finger clean. !”
Researchers used a scanner to look inside the skull and hand of an aye-aye specimen at the museum and found the finger could go all the way to the throat.
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Previous scientific research has suggested that there may be health benefits to eating snot, but researchers believe that in this case it’s possible that the animal ingesting its own mucus is simply due to its texture, its crunchiness and salinity.
Roberto Portela Miguez, senior curator at the Natural History Museum and co-author of the paper, said, “It’s great to see how museum specimens and numerical methods can help us elucidate behaviors that are typically quite difficult to observe in their natural state. habitat.
“We hope that future studies will build on this work and help us understand why we and our close relatives insist on picking our noses.”