Aye-aye, Daubentonia madagascariensis

The aye-aye (Daubentonia madagascariensis) is a species of lemur that is native only to the island of Madagascar. This species is the only remaining member in the Daubentonia genus. Its range is slightly fragmented in some areas. It derives its scientific name from Louis-Jean-Marie Daubenton, a French naturalist, and from the island on which it was first discovered. Aye-ayes prefer a habitat within deciduous forests or rainforests, with most occurring in rainforests, but can inhabit plantation as well.

Some Malagasy people call it the “hay-hay”, a name derived from a noise it supposedly makes, although it does not actually emit that vocalization. It is thought that this is where its European name was derived. It is also thought that its common name is derived from a startled exclamation of a Malagasy native when encountering the aye-aye, as a European overheard “aiee!-aiee!” This is not likely, however, because the name occurs in remote villages of the aye-aye’s range, where Europeans were not present. There is one theory that states that the aye-aye’s name derives from the Malagasy term for “I don’t know.”, “heh-heh”, which was thought to be used in place of the name of a magical creature.

The aye-aye bares a few unique features that differentiate it from other lemur species. Its fingers, which are squirrel like, allow it to feed much like a woodpecker, by tapping on branches and removing grubs. Its teeth resemble those of a rodent, causing some confusion among early discoverers, who placed it under the Rodentia order. Its skull and facial structure resemble a cat’s, causing even more confusion on its taxonomy.

Although it is classified as a primate, this status has not been accepted as completely true. Anthony and Coupin placed it within the infraorder Chiromyiformes in 1931. Colin Groves kept this classification because he was not entirely sure that the aye-aye should be classified with the rest of the lemurs found on Madagascar, although genetic testing did show that the aye-aye was closely related to the lemurs. Physical features that the aye-aye shares with other lemurs include virtually identical teeth, shorter hind legs, and bones known as petrosal bullae, which surround the ossicles in the ear.

The aye-aye can vary in color depending on age, with young individuals appearing to be silver in color. When the aye-aye gets older, it will bare thicker and darker to yellowish fur that can be tipped with white on the head and dorsal fur. The average body length of the aye-aye is approximately three feet, with a tail that can grow to be longer than the body. The third finger of this species is used for grooming and tapping branches, while the fourth finger is used to remove food from the branches.

It was thought that the aye-aye was a solitary creature, but more recent studies have shown this to be false. Although it typically forages alone within its home range, male ranges typically overlap with those of other males and females, and grooming is quite common when two aye-ayes encounter each other. However, female home ranges do not overlap, most likely due the small size of about 20 acres. Male home ranges are larger, encompassing up to 80 acres.

Aye-ayes will use scent marking to denote territory, as well as alert other aye-ayes of their presence. Females are dominant, which is common among primates, and there are often many confrontations between females during mating season. Males are sometimes aggressive during mating as well.

The diet of the aye-aye consists of animal materials, fruits, nuts, insect larvae, fungi, and seeds. When eating fruit, it will simply grab pieces from branches as it moves through the canopy. In areas where it is not within its natural habitat, like plantations, it is known to steal crops and have a preference for vegetables and sap.

Foraging is a special skill of the aye-aye, and it is the only primate known to use echolocation to find food. It will tap branches to locate grubs, and remove them by using the fourth finger. These nocturnal primates can spend up to eighty percent of their active time foraging for food in the trees. It moves through the trees in the same manner as a squirrel, rarely climbing down to move to another tree. It can cross as much as 2.5 miles while searching for food and occasionally, foraging is done in groups.

The aye-aye has been considered a symbol of death for the Malagasy people, and is also considered an annoyance due to its adaptability to live near plantations and steal crops. Because of its association with death, it is typically killed quickly. Despite this, the aye-aye has been recorded as a brave primate, moving about on city streets and even walking up to naturalists in the forests.

Deforestation, poaching, hatred from humans, and killing for crop protection are the major threats to this species, which was previously thought to be extinct. However, in 1957, it was re-discovered, and nine individuals were taken to an island off the east coast of an island near Madagascar, called Nosy Mangabe. Poaching cannot be stopped, and because the Malagasy people are poor and overpopulating the island, the aye-aye will continue to dwindle in number.

However, nearly 50 individuals can be found in zoos across the world. The most prominent places for this is Duke Lemur Center located in Durham, North Carolina. Many aye-ayes have been bred in the zoo, and much beneficial research has been conducted. The aye-aye appears on the IUCN Red List with a conservation status of “Near Threatened”.

Image Caption: Aye-aye (Daubentonia madagascariensis). Credit: Tom Junek/Wikipedia (CC BY-SA 3.0)