The secret of the elongated finger of the aye-aye revealed… And it is not appetizing!

Spread the love

The secret of the extended finger of the aye-aye revealed… And it is not appetizing!

Aye-aye is a primate nocturnal lemur.

The aye-aye is the newest addition to the exclusive club of animals that clean their noses with their fingers and eat the mucus found there.

This primate from the size of a big cat, which inhabits the forests of Madagascar, can however count on a formidable tool to manage to reach its nasal pantry that no other animal species has: a narrow finger 8 centimeters long.

The eight centimeter long finger of the aye-aye goes through the nose to reach the throat and collect the mucus that is there.

Since its first description in 1782 by the French naturalist Pierre Sonnerat, the aye-aye has not ceased to intrigue scientists because of its singular appearance, to say the least.

The aye-aye (Daubentonia madagascariensis) is a 75 to 90 cm long (44 to 53 cm only for the tail) insectivorous and frugivorous lemur whose incisors are reminiscent of those of rodents, the pointed ears those of bats and the bushy tail that of squirrels.

The aye-aye is a primate the size of a large cat.

Ayes-ayes also have six fingers on each hand, including a pseudo-thumb that helps them grip. But the animal is especially endowed with two extremely long fingers. Biologists have long thought that it was used to reach insects hidden under the bark, to groom and scratch. However, recent observations made by an international team of scientists show that this lemur inserts its entire extra-long middle finger into its nasal passages up to the throat, then licks it and ingests the collected nasal mucus.

Beginning of the widget . Skip the widget? The following video shows an aye-aye cleaning his nose. End of the widget. Back to top of widget?

Using a finger to pick the nose, a behavior called rhinotillexomania, is seen in at least 12 other species, including humans, chimpanzees, macaques, and gorillas.

In their work published in the Journal of zoology (in English), researchers announce that they have observed this behavior for the first time in a captive aye-aye nicknamed Kali who lives in a sanctuary in North Carolina.

The zoologist Anne-Claire Fabre and her colleagues also describe in their study the internal anatomy of the nasal cavity of the aye-aye and explain how the animal can introduce its entire finger into its nose to reach the pharynx. They also document other primate species that pick their noses.

Does this ability to insert a finger in the nose help relieve irritation, support the immune system? The authors would now like to carry out further studies to better document the behavior in other species of primates and in vertebrates and, thus, perhaps succeed in explaining its functional role and its evolutionary interest.

One ​​thing is certain, this behavior seems to be linked to a species' ability to finely manipulate objects.

We find that this behavior is observed in species that have great dexterity, notes in a press release Roberto Portela Miguez, of the Museum of Natural History in London.

“Non-primates may not possess the same dexterity sufficient to clean their noses. It could be a phenomenon that occurs in us and in species close to ours.

— Roberto Portela Miguez, Natural History Museum, London

This study also found that many primates use tools, such as twigs, to pick your nose. This reality suggests that species whose fingers are not small enough to enter the nostrils might be inclined to use instruments to reach the nasal mucus.

Previous Article
Next Article