Do you know aye-aye, a primitive monkey that lives only on the island of Madagascar?
By the way, a song was created in Japan under the title “aye-aye”, and as of 2023, it is still sung as a nursery rhyme.
Therefore, there are a certain number of people who have an image of aye-aye in Japan with a cute atmosphere.
However, in fact, on the island of Madagascar, where it lives, it is also an animal that is feared as the incarnation of the devil.
Let’s take a peek at what characteristics and interesting secrets aye-aye have in this article!



~ Basic information. ~

Mammalia-Primates-Daubentoniidae-Aye-aye genus.

Length:30~40cm weight:2~3kg.

Aye-aye is a very primitive member of the monkey family, and it is an animal classified as a primate like us humans. The body color is black or dark brown, and it is characterized by its large eyes, elongated fingers like wire, and a long bushy tail, which looks like a squirrel, bat, and monkey combined.


When the aye-aye was first discovered in the 18th century, it was thought to be a member of the squirrel family due to its appearance and the fact that its front teeth continued to grow. However, it was not until about 100 years later that it was discovered that it was not a squirrel but a member of the monkey family. The aye-aye originally had a small population, and by around 1980, no one had ever photographed a wild aye-aye. Some people even thought that it had already become extinct.

The aye-aye is a nocturnal animal that lives alone except during breeding season and child-rearing. It spends almost all of its day on trees and rarely comes down to the ground. It reaches sexual maturity at around 2-3 years old and can reproduce after a pregnancy period of about 155 days. It usually gives birth to one baby at a time.



Aye-aye’s Q&A.

Where does the name aye-aye come from? 

The name “aye-aye” is believed to come from the Malagasy word “hi-hi,” which means “I don’t know.” The scientific name is “Daubentonia madagascariensis.” By the way, it is also called “yubizaru” in Japan.

出典:Aye-aye_(Daubentonia_madagascariensis)_2.jpg: Tom Junekderivative work: WolfmanSF, CC BY-SA 3.0, ウィキメディア・コモンズ経由で

Why do aye-aye live there?

Aye-aye is endemic to the island of Madagascar and is one of the monkeys with primitive characteristics.

It is believed that monkeys, including aye-aye, migrated to Madagascar thousands of years ago and evolved independently on the island of Madagascar, which is far from other continents, and still inhabit it today.

However, fossils of animals thought to be close to aye-aye have been found in Egypt and Kenya in Africa, and there is a theory that “the ancestor of aye-aye separated from other lemurs after crossing to the island of Madagascar and became aye-aye.” and “Aye-aye’s ancestor came to Madagascar at a different time than other monkeys and became aye-aye.”

In the past, Madagascar Island was home to aye-aye, which is larger than today’s aye-aye, but unfortunately it is thought to have become extinct.


What are aye-aye eating?

The aye-aye is an omnivorous animal that feeds mainly on the seeds of a type of fruit called “ramy” in the wild. It also eats fruits, insect larvae, and flower nectar but does not eat adult insects.

In zoos, it eats vegetables (such as avocado and cucumber), fruits (such as papaya, lychee, mango, orange, and persimmon), walnuts, peanuts, mealworms, and honey.

Is it true that aye-aye’s fingers have an unusual shape?

It’s true.

The aye-aye has five fingers, but its middle finger is very long and thin compared to its other fingers and looks like a piece of wire. The tip of the middle finger can move freely, but it cannot grasp objects. In fact, the aye-aye uses this unusual middle finger to extract the contents of the seeds of its main food source ramy.


The seeds of ramy are very hard and are said to be three times harder than walnuts. When the aye-aye eats the seeds of ramy it first holds them firmly with both hands and blows away the flesh until it can see the seeds. Then, it uses its sharp front teeth in its lower jaw to bite into the seed and make a hole. It then sticks its middle finger into the hole and skillfully scrapes out only the contents to eat.

The aye-aye has a habit of tapping its middle finger on food before eating it to determine whether it can eat it by judging its hardness and thickness. This is thought to be a habit that has developed so that the aye-aye can obtain food reliably because there are three rooms in the seed of ramy and only the large room contains contents.


The aye-aye’s dexterity can also be seen in zoos, where it has been observed eating only the contents of oranges and persimmons, leaving only the thin skin behind. It has also been observed tapping its finger on a bamboo tube to find mealworms inside and accurately opening a hole to eat them.

Is it true that aye-aye are said to be the embodiment of demons?

It’s true.

The aye-aye has long been considered a scary animal that brings bad luck and misfortune in Madagascar because it is thought to be an incarnation of demons and evil spirits.

Today, animal research has advanced around the world, and the name and appearance of the aye-aye are known worldwide. However, in an era when research on animals was not advanced, if you encountered an aye-aye with its big round eyes staring at you in the forest, it would not be strange to be scared or surprised by its indescribable appearance.


Why is there a difference between the nursery rhyme “aye-aye” and the local image?

Aye-aye is sung in the very famous nursery rhyme “aye-aye” in Japan.

In fact, this song is so brightly made that when you listen to it, you think that aye-aye is a cute animal. But why did an animal that is thought to be the embodiment of the devil become a cute image in Japan?

It is said that this is because the lyricist saw aye-aye in the pictorial book when creating the lyrics of this song and made the lyrics from the sound of the cute name. It’s kind of strange that so many Japan people sing and know about animals that live only in Madagascar.


Can aye-aye be kept as a pet?

When breeding rare animals at home, it is necessary to follow the established laws in some countries. This time, we will introduce whether it is possible to breed aye-aye at home in Japan.

The aye-aye is a very valuable animal, so it is classified as “Appendix I” under the Washington Convention as “species threatened with extinction due to trade or potential trade.” Animals classified as Appendix I are protected worldwide and cannot be traded between countries unless there are special purposes such as research.

In particular, because the aye-aye is protected by law, it is very difficult to obtain even in facilities such as zoos that aim to protect and breed animals. For this reason, it is almost impossible for individuals to obtain and keep aye-ayes.


Is there a place to see aye-aye in Japan?

As of 2021, only Ueno Zoo in Tokyo breeds and exhibits aye-aye at zoos in Japan.

Aye-aye are internationally protected animals, and although it is somewhat old information, as of 2001, only 40 animals were bred worldwide. Considering this situation, it is unlikely that the number of breeding facilities in Japan will increase easily in the future.

Ueno Zoo is conducting joint research on aye-aye in cooperation with the Madagascar National Tsimbazaza Zoo, and in 2001 a male and female pair was awarded. Since then, it has been successfully bred 10 times.


What is the lifespan of aye-aye?

The lifespan of aye-ayes in the wild is unknown, but it has been confirmed that they can live for about 20 years in captivity.

Since research on aye-ayes is still ongoing, we hope that more detailed information about their ecology, including their lifespan in the wild, will be revealed in the future.


What enemies does aye-aye have?

Wild aye-aye seem to be preyed on by fossa, a carnivore that lives only on the island of Madagascar.


However, for aye-aye, the greatest natural enemy is not Fossa, but us humans.

“Is it true that aye-aye are said to be the embodiment of demons?” As explained in the section, aye-aye has long been considered a very unlucky animal on the island of Madagascar.

In addition, because aye-ayes sometimes eat crops such as mangoes and coconuts, it was considered natural to kill them immediately upon discovery in their natural habitat. Unfortunately, aye-ayes were not afraid of humans and were easy to catch and kill.

In addition, tropical rainforests have been burned down for agriculture, trees have been cut down for grazing livestock (primarily cattle) and farming, and the places where aye-ayes can live have been rapidly reduced. As a result, aye-ayes are on the verge of extinction. Although they are now protected internationally, environmental destruction on Madagascar Island is progressing daily, and their future is not bright.

The aye-aye is classified as “Endangered (EN)” on the International Union for Conservation of Nature (IUCN) Red List because it is at high risk of extinction in the wild in the near future.






島泰三(2006年)『マダガスカル アイアイのすむ島』草思社



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