"We found that the aye-ayes immediately went for the plugs that weren't fixed in place, even though they were so tight that you couldn't see them. We realized they didn't even need a cavity to detect, just a crack."
Now that he has established the limits of the aye-ayes detecting ability, Erickson is attempting to understand their foraging strategy. In his latest experiments, he has created subsurface mazes, and then refilled them with packed sawdust, just as a boring insect would leave behind as it ate through the wood. He next opened hollows in the sawdust at various places along the track, adding mealworms to some and nothing to others.
"I thought that the animals might tend to look for the ends of tracks, where the insect would most likely be," he said. "But I found that aye-ayes were just as good finding grubs midway along the track as at the end. And contrary to my earlier studies, it did seem that the actual presence or absence of prey made a difference."
Erickson also is exploring how infants acquire the tapping strategy. He has constructed large cavity-filled wood blocks with up to 50 cavities, so that mothers and infants can work together.
His studies will significantly aid the aye-aye's future survival, because understanding how the primates forage naturally is a key to preserving that ability. Such foraging will be literally a life or death skill if captive-born aye-ayes are ever to be returned to the wild.
"We now have enough of these young animals reaching maturity so that we can compare wild caught with captive born," said Erickson. "That's really important, because we want to make sure that we're giving them all they need to be real aye-ayes. If we ever think about re-introduction of these animals, we want to make sure they have all the skills that they need."
The Duke Primate Center, located in a section of Duke Forest, is home to
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Contact: Dennis Meredith
Dennis@dukenews.duke.edu
(919) 681-8054
Duke University
8-Jul-1998