Due to its bizarre appearance and unusual feeding habits, the aye-aye is considered by many to be the strangest primate in the world. It is the world’s largest nocturnal primate. Unusual physical characteristics include incisors that are continually growing (unique among primates), extremely large ears, and a middle finger which is skeletal in appearance, and is used by the animal as a primary sensory organ.
Additional information about the DLC’s aye-ayes — from our first imports to the present — can be found in our WINTER 2017 newsletter, devoted exclusively to these rare and amazing lemurs. Our newest infant, Agatha, is the subject of the article “Rare aye-aye born at the Duke Lemur Center,” published September 21, 2017. See video footage, too, of month-old Agatha during her routine weigh-ins.
Pictured above: The aye-aye's long, thin middle finger is essential for locating and "hooking" insect larvae for the aye-aye to eat. Click the image for a larger view.
Diet: The aye-aye’s diet is highly specialized, consisting mainly of the interior of Ramy nuts, nectar from the Traveller’s Palm tree, some fungi and insect grubs. The animals are also known to raid coconut plantations, and have been seen eating lychees and mangoes, which are also plantation crops. Most of what we know about the diet and social behavior of wild aye-aye populations is based on a two year study in the early nineties by Yale University Undergraduate, Eleanor Sterling.
Tap-foraging: Since a significant percentage of an aye-aye’s diet consists of insect larvae that dwell inside dead or living trees, the animals have evolved a specialized method for locating the larvae. As they walk along a branch, the animals continuously and rapidly tap it with their middle finger. Cupping their huge ears forward, the aye-aye listens intently to the echoing sounds coming from the tapped tree. When the sound indicates they are above an insect tunnel, the animals begin to tear off enormous chunks of the outer bark with their impressive teeth, until the insect tunnel is revealed. Then the aye-aye inserts its slender and highly flexible third finger into the hole, and when the prey is located, it is hooked with the tip of the finger and removed.
HERE is a video of two aye-ayes, Ardrey and her daughter Elphaba, using the same process to eat eggs as they would to locate and eat insect larvae that dwell inside trees. First they tap, then they chew, and finally they use their long flexible middle fingers to dip into and remove the yolks of the eggs. When they finish, the delicate eggshells remain fully intact, except for the small hole created by the aye-ayes’ strong front teeth!
Written by David Haring, the DLC's longtime registrar and photographer, the article "The DLC's Founding Aye-aye Fathers (and Mothers)" discusses how the DLC unraveled the secrets of aye-aye husbandry in the 1980s -- including what to feed these mysterious and, at the time, little studied lemurs.
Click HERE to see Agatha, a five-month-old infant aye-aye, learning how to tap-forage from her mom, Medusa.
Click HERE to read Carl Erickson's research paper, "Tap-scanning and Extractive Foraging in Aye-ayes," published in Folia Primatologica.
HERE is another video: Watch two aye-ayes, Ardrey and her daughter Elphaba, using the same process to eat eggs as they would to locate and eat insect larvae that dwell inside trees. First they tap, then they chew, and finally they use their long flexible middle fingers to dip into and remove the yolks of the eggs. When they finish, the delicate eggshells remain fully intact, except for the small hole created by the aye-ayes’ strong front teeth!
Adopt an aye-aye: Want to learn more about aye-ayes AND help support their care, not only here but in Madagascar? Consider symbolically adopting Agatha, a young female aye-aye, through the DLC's Adopt a Lemur program! Adoption packages start at just $50.
Send an aye-aye a present: You can send special treats like coconuts to the DLC's aye-ayes, as well as raw materials for us to construct special enrichment activities to keep them happy and healthy. Simply visit our amazon wishlist! Aye-ayes in particular love coconuts, coconut milk, peanut butter, tamarinds, and any of the fun treats labelled "aye-aye enrichment item."
Spread the word: This spring, 7-year-old Hailey wrote to us asking if we’d consider posting her best drawing of an aye-aye – her favorite animal in the world – so others could learn more about these amazing lemurs and why it’s important for us to save them.
Thank you so much, Hailey, for helping the DLC save lemurs! Your love for aye-ayes and your desire to teach people about them is inspiring, and it means so much to us. You’ve already made a positive difference, and you’re just getting started!