At only a couple of pounds, the gangly creature named Angelique hardly seems like the centerpiece of an historic event in the preservation of her highly endangered species. But the little aye aye is, indeed, just that. She is the first of her species ever born to parents who were themselves born in captivity.
Angelique's successful birth last September was a signal event, because the ancient primates known as aye ayes are notoriously complex social creatures. And the achievement of the Duke Primate Center -- more specifically Assistant Director Dean Gibson -- in coaxing Angelique's inexperienced father to mate yielded important insights into the requirements for breeding aye ayes in captivity.
The strange primates are fascinating both in themselves and as examples of the ingenuity of evolution. Their evolution began some 60 million years ago, when their line split off from their fellow lemurs on the island of Madagascar. Since then, they have adapted magnificently to occupy the ecological niche that elsewhere is the province of woodpeckers. The difference is that aye ayes use batlike ears and finger-tapping to detect grubs hidden beneath tree bark; beaverlike teeth to gnaw into the wood to expose them; and the dexterous fingers with hooked nails to fish them out.
Today, aye ayes are extremely rare on Madagascar, both because of deforestation and because local superstition holds that if an aye aye points a finger at a person, that person is doomed. Thus, the gentle animals are killed on sight.
Since the Primate Center first brought aye ayes into captivity some two decades ago, they have been successful in maintaining the animals. In fact the center was the site of the first captive aye aye birth -- Blue Devil, born in 1993. However, all aye ayes at the center have, until Angelique, been born of fathers socialized in the wild -- apparently where they learned the art of mating.
So, when it came time for these first-generation offspring to mate, the center was faced with teaching na¯ve male aye ayes the arts of lemur love.
"Even though the wild-caught animals reproduced well, the males from that first generation were not showing any signs of interest in breeding, well beyond the years that the first-generation females had already started cycling and breeding," said Gibson. "The males at four to five years of age were clueless and knew nothing about breeding."
One of these males was Merlin. Despite having been on a "honeymoon" at the San Francisco Zoo for two years with another female, Caliban, Merlin showed no ability to breed. Determined to ensure the continuation of the breed, Gibson paired Merlin with the captive-born female Ardrey who had breeding experience with a wild male. The result was sparks, but not of love.
"Merlin was scared to death of her, didn't know what to do," said Gibson. Instead of performing the requisite behaviors of sniffing and mating, said Gibson, Merlin would sniff and run away, apparently unsure what to do next. And Ardrey would take annoyed swipes at the reluctant suitor.
"It took two years of catching her in her breeding cycle, putting Merlin with her everyday during her cycle, coaching him along and stopping her from being aggressive towards him," recalled Gibson. "I'd stand there with a net, and defend him, and when he was doing well, give him nuts.
"Also, I'd give her treats to calm her down, so she'd sit there and eat, rather than attack him," she said. Eventually, Gibson's coaching was successful, and the animals bred. Gibson's reward from the animals was by no means their gratitude. "Ardrey was hateful afterwards; she even smacked me in the head." Nevertheless, Gibson did receive an ultimate gratification for her efforts, in the form of Angelique.
The experience with the aye ayes has taught the center's primatologists an invaluable lesson -- that the complex creatures need socialization to mate. Thus, said Gibson, "We've introduced Tolkien, a younger male, with Merlin to maybe get some competition going; because in the wild, when a female starts to cycle, she'll call and present herself, and males will come in and compete." Gibson reports that the young Tolkien appeared to learn mating skills from Ardrey as well as the now-experienced Merlin.
According to center Director Anne Yoder, the animals' need for natural socialization is also driving design of planned new housing at the center.
"We need to build facilities so that these animals can live in the social structure required for their natural reproductive behaviors to emerge and continue," said Yoder. "Otherwise, we might find ourselves housing the last aye aye, or the last examples of other of these endangered lemurs.
"Dean showed us through her amazing coaching efforts to promote the aye aye's mating how important this socialization is -- that their behaviors are so much more sophisticated than one would ever suppose, given the traditional belief that lemurs are merely hard-wired for behavior," said Yoder. Thus, she said, the center plans include "aye aye atriums," spacious facilities that will allow a full range of socialization among the animals.
And for other lemurs, the new facilities will feature indoor housing amidst outdoor fenced enclosures. Thus, during the winter, the animals can be released on warm days, but brought into the buildings when temperatures drop.
Not only will such flexible arrangements relieve the animals' social stress from being housed indoors all winter -- as is now the case. They also will enable researchers to continue lemur behavior studies year-round, said Yoder.
Such studies, she said, will yield scientific surprises about the primates that, isolated on Madagascar, evolved into a rich array of species in parallel with anthropoids in the rest of the world. Also critically, said Yoder, the studies will yield knowledge that will enable preservation of the exotic, endangered primates.