National Geographic : 2008 Mar
motives, imitating others, and being creative. Bit by bit, in ingenious experiments, research ers have documented these talents in other species, gradually chipping away at what we thought made human beings distinctive while offering a glimpse of where our own abilities came from. Scrub jays know that other jays are thieves and that stashed food can spoil; sheep can recognize faces; chimpanzees use a variety of tools to probe termite mounds and even use weapons to hunt small mammals; dolphins can imitate human postures; the archerfish, which stuns insects with a sudden blast of wa ter, can learn how to aim its squirt simply by watching an experienced fish perform the task. And Alex the parrot turned out to be a surpris ingly good talker. Thirty years after the Alex studies began, Pepperberg and a changing collection of assis tants were still giving him English lessons. The humans, along with two younger parrots, also served as Alex's flock, providing the social input all parrots crave. Like any flock, this one-as small as it was-had its share of drama. Alex dominated his fellow parrots, acted huffy at times around Pepperberg, tolerated the other female humans, and fell to pieces over a male assistant who dropped by for a visit. ("If you were a man,"Pepperberg said, after noting Alex's aloofness toward me, "he'd be on your shoulder in a second, barfing cashews in your ear.") Pepperberg bought Alex in a Chicago pet store. She let the store's assistant pick him out because she didn't want other scientists saying later that she'd deliberately chosen an especially smart bird for her work. Given that Alex's brain was the size of a shelled walnut, most research ers thought Pepperberg's interspecies commu nication study would be futile. "Some people actually called me crazy for trying this" she said. "Scientists thought that chimpanzees were better subjects, although, of course, chimps can't speak." Chimpanzees, bonobos, and gorillas have 44 NATIONAL GEOGRAPHIC * MARCH 2008 been taught to use sign language and symbols to communicate with us, often with impressive results. The bonobo Kanzi, for instance, carries his symbol-communication board with him so he can "talk" to his human researchers, and he has invented combinations of symbols to ex press his thoughts. Nevertheless, this is not the same thing as having an animal look up at you, open his mouth, and speak. Pepperberg walked to the back of the room, where Alex sat on top of his cage preening his pearl gray feathers. He stopped at her approach and opened his beak. "Want grape" Alex said. "He hasn't had his breakfast yet," Pepperberg explained, "so he's a little put out." Alex returned to preening, while an assistant prepared a bowl of grapes, green beans, apple and banana slices, and corn on the cob. Under Pepperberg's patient tutelage, Alex learned how to use his vocal tract to imitate al most one hundred English words, including the sounds for all of these foods, although he calls an apple a "ban-erry." "Apples taste a little bit like bananas to him, and they look a little bit like cherries, so Alex made up that word for them," Pepperberg said. Alex could count to six and was learning the sounds for seven and eight. "I'm sure he already knows both numbers," Pepperberg said. "He'll probably be able to count to ten, but he's still learning to say the words. It takes far more time to teach him cer tain sounds than I ever imagined." After breakfast, Alex preened again, keeping an eye on the flock. Every so often, he leaned forward and opened his beak: "Ssse... won." "That's good, Alex," Pepperberg said. "Seven. The number is seven." "Ssse...won! Se...won!" "He's practicing," she explained. "That's how he learns. He's thinking about how to say that word, how to use his vocal tract to make the correct sound."