3

BIRDS WITH BRAINS

In the very earliest times, when both people and animals
lived on earth, a person could become an animal if he wanted
to, and an animal could become a human being. Sometimes
they were people and sometimes animals and there was no
difference. All spoke the same language. That was the time
when words were like magic.

NALUNGLAQ, A NETSILIK ESKIMO

Nearly all the scientists I met for this book wished they could talk to their animals. “Of course, it would be much easier if I could ask them these questions,” they would say. “But since that’s not possible, I have to find another way” to get inside their minds. Many of them had dreamed that they talked to their animal and that he or she talked back. They envied Doctor Doolittle.

But what if you could ask your animal questions—just speak to him or her directly, and get a reply? Would we better understand the minds of our fellow creatures?

Irene Pepperberg used this approach with Alex, her male African gray parrot, whom she called her “close colleague.” She used those words so that other people (primarily her human colleagues) would understand that Alex wasn’t her pet and that she wasn’t emotionally attached to him. She wasn’t Alex’s soccer mom, rooting for him to pass the cognitive challenges she gave him. She wanted to understand objectively how the minds of birds—specifically, parrots—worked.

I met Alex and Pepperberg in her lab at Brandeis University in Massachusetts, where she is an adjunct professor. Sadly, Alex has since died from a heart arrhythmia, but at that time he and Irene were in the twenty-ninth year of what Pepperberg called their Avian Learning Experiment. (Alex’s name was an acronym derived from that title.) They had come closer than any human-animal pair ever has to achieving the seemingly impossible dream of verbal interspecies communication.

“I thought if Alex learned to communicate, I could ask him questions about how parrots see the world—how they reason. It would be a new way to understand avian cognition,” Pepperberg told me.

Pepperberg and Alex were seated—she at a small desk, he on top of his cage—in her lab. She was stylishly dressed in a gray miniskirt and rose-colored sweater, colors that suited her complexion and dark hair and eyes. Gray and red are also the two main hues in the plumage of African gray parrots. When Pepperberg stood next to Alex, they looked like a human-bird version of a mother-toddler pair dressed in matching sweater sets. Pepperberg said she chose the colors not because they were those of her parrots but because they looked good on her. She wasn’t a crazy bird lady. Nevertheless, there was something charming about the two being “dressed alike”—something that suggested a warmer relationship than the words “close colleague” allowed.

It was just after 8:30 a.m., and Pepperberg’s two assistants were standing at a sink about three steps away from her desk, chopping apples and bananas for Alex and two other African gray parrots, Griffin and Arthur. They were perched in the back of the room, which was small and narrow, across from Alex. The lab’s walls were covered with beige, sound-deadening curtains, making the room seem all the more cramped. Pepperberg had squeezed in a chair for me next to hers. She was simultaneously sorting through her mail, introducing me to everyone, and explaining the parrots’ routine. The staff had already tidied their cages and spread clean newspapers on the floor, and the parrots were now waiting to be fed.

The humans and the two younger parrots served as Alex’s flock, Pepperberg explained, providing the social input all parrots crave. Alex was the oldest bird, and, I quickly deduced, everyone (human and parrot) catered to him. Like any flock, this one—as small as it was—had its dramas. 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 stopped by for a visit. For some unknown reason, when it came to what might be called social affairs, Alex always preferred men, especially tall, blond men, like this assistant. “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—that’s the parrot equivalent of love.”

As it was, Alex gave me a quick glance, decided I wasn’t his type, and ignored me. So, like a groupie, I could study him—the world’s most famous bird!—in great detail from just a few feet away. Alex was about a foot long, from head to tail, and each of his dove gray feathers was trimmed with white as if edged with lace. White feathers framed his yellow eyes and set off his black, scimitar-shaped beak. Usually he had long, bright rose red tail feathers, too, Pepperberg said, but he was molting, and his “gorgeous tail” was but a stub. The two other parrots looked very much like him, although Griffin was bigger, but neither bird had Alex’s confidence. They were wary of me and trembled if I looked their way, so I took my cue from Alex and ignored them.

“Parrots are slightly neophobic, afraid of new things and people,” Pepperberg said, explaining Griffin’s and Arthur’s shivering feathers.

After Griffin and Arthur settled down, Pepperberg explained the parrots’ lessons. All the birds were learning to emit what Pepperberg called “English labels” (that is, the sounds for objects) via a method she termed the “model/rival technique.” Without going into all the details, here’s a brief example of how this works: a parrot would be placed on a perch between two people. One of the people would hold up an item, such as a piece of wood, and ask the second person, “What’s this? “Wo-od,” the second person would reply, drawing the sound out in an enthusiastic singsong manner. The first person would then give the piece of wood to the second as a reward. This sequence would be repeated several times, with the humans taking turns playing the two roles, so that the parrot would learn from either one. Eventually, one person would ask the parrot the question. When the parrot replied, even initially with a poorly articulated version of the word, he, too was given the piece of wood.^* This was how the birds learned English labels. In her scientific publications, Pepperberg always studiously avoided the word words for the sounds that the parrots knew. Alex, who had been working at this the longest of the three, was the most advanced and had acquired about one hundred labels. (In his classes, Alex actually preferred women teachers over men, even tall, blond ones. Alex may have thought the men were trying to dominate him, Pepperberg said.) Pepperberg was also investigating the visual systems of parrots by testing Alex’s ability to perceive optical illusions—such as two parallel lines joining together in the distance—as we humans do.

Not so long ago, most scientists would have chuckled at these types of studies. Birds have small brains after all and, like fish, were thought to be missing the key neural areas that make cognition possible. Until the late twentieth century, most bird behaviors were considered innate and unchanging. For nearly three decades Pepperberg had struggled against this misperception, and the cost showed in the tiny lab she had to rent and in her relieved smile when she opened a letter and found a check for a generous donation to the Alex Foundation tucked inside. It would help her cover the expenses of the lab and parrots.

Pepperberg explained that she was between grants. Her last one had run out about eight months before I met her; she did not have a job, other than teaching one psychology class at Harvard, and sometimes had to get by on unemployment benefits. “I’m living on tofu these days,” she said. She gave a wry smile and shrugged.

Throughout most of her career, she had struggled to keep her project with Alex and the other parrots going, a problem that many researchers working on long-term projects with animals face. Pepperberg, though, thought her troubles were tied to her specific study animals—parrots—and her efforts to get inside their minds by communicating with them. “It makes too many mainstream scientists uncomfortable,” she said, “so getting grants has always been a challenge.” Yet over the years she’d received impressive awards and grants, including several from the National Science Foundation and a Guggenheim Fellowship. Because these rarely lasted more than a year or two, Pepperberg, who’d given up a tenured university professorship to accept what turned out to be a short-lived position in the Boston area, seemed constantly to be scrounging for funds as she was now. She’d started the Alex Foundation, a nonprofit organization, in 1991 in part to help her get through the lean times.

Pepperberg had been working with Alex since 1977. She’d bought him at Noah’s Ark, a Chicago-area pet store, when he was about one year old. She’d let the store manager pick out a bird for her so that scientists couldn’t accuse her of choosing a particularly smart bird. Given that Alex’s brain was the size of a shelled walnut, most researchers thought her study would be futile.

“Some scientists said to me, ‘How can you possibly do an experiment like this? Parrots don’t have brains.’ People actually called me crazy for trying it. You know, ‘What are you smoking?’ Most scientists thought that chimpanzees were better subjects for this kind of work, although, of course, chimps can’t speak,” Pepperberg said.

The revolution in animal cognition studies was in its very early stages when she launched her project. Only the year before, Donald Griffin had published his book The Question of Animal Awareness, which opened the door to the idea that animals have minds of their own. Pepperberg boldly switched fields (at the time, she was completing a PhD in theoretical chemistry at Harvard) to join the movement, after watching two television programs. One showed scientists using sign language to communicate with apes and dolphins; the other was about how birds learn their songs. The shows “were a revelation to me,” she later recalled in her book Alex and Me. “I had no idea what I would do nor how I would do it … but I did know—instantly and inescapably—that this was where my future lay.” Never a quitter, Pepperberg finished her PhD in chemistry—while also attending as many animal behavior and language acquisition classes as she could, and reading every animal communication study she could lay her hands on. After being awarded her doctorate, she didn’t stop to rethink her “new calling” either. Instead of looking for a chemistry-related job, she puzzled over which animal she should study.

Most researchers in the young field of interspecies communication were working with primates and cetaceans because they are closely related to humans or have large brains and, at the time, were thought most likely to have some form of humanlike communication skills. But Pepperberg, who as a child had trained parakeets to speak a few words and had kept parakeets as pets throughout her college years, thought she would have more success with a parrot.

“Parrots, especially African grays, are very good mimics,” she said. “There were a few studies about the social lives of parrots and how they probably use their complex calls to keep track of the members of their flocks. So, although I hadn’t raised a parrot before, I thought it made more sense to work with an animal that could vocalize”—even though parrots are far removed from the human family tree.

Pepperberg also discovered that German scientists had worked with African grays in the 1950s and 1970s. They had found that these parrots had a surprising understanding of numbers and quickly learned human speech by interacting socially with people.

Anyone who has a pet parrot knows that they readily imitate human sounds. That doesn’t mean that they understand the sounds that humans make; what parrots can do is to learn to associate certain sounds with certain behaviors. If you always say, “Good-bye” when you go out the door, for instance, your parrot may come to associate that sound with your action of leaving. Your parrot may even say good-bye as you exit the door. You don’t, however, expect to have a conversation with your parrot, and neither did Pepperberg. She did think that if Alex understood the association of sounds with certain objects, she might be able to ask him some questions about his perception of the world.

Over the years, some scientists have taught chimpanzees, bonobos, and gorillas to use sign language and symbols to communicate, often with impressive—if controversial—results. The bonobo Kanzi carries his symbol-communication board with him so he can “talk” to his human researchers, and he has invented combinations of symbols to express his thoughts. Nevertheless, this is not the same thing as having an animal look up at you, open his mouth, and speak spontaneously.

Pepperberg and I 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 closed his eyelids halfway, hunched his shoulders, and looked at her. His narrowed eyelids and hunch made him look crabby.

“Don’t look at me like that,” Pepperberg said to him. “See, I can do it, too.” She narrowed her eyes and gave him a stony look, imitating his expression. Alex responded by bending his head and pulling at the feathers on his breast.

To me, she said, “He’s in a bad mood because he’s molting, and sometimes when he’s like that he won’t work.” She spoke to Alex again, “You’ll get your breakfast in a moment.”

“Want wheat,” Alex said.

Arlene Levin-Rowe, the lab manager, handed Pepperberg a bowl of grapes, green beans, apple and banana slices, shredded wheat, and corn on the cob. Pepperberg held up the sliced fruits and vegetables for Alex, who seized them with his beak. Sometimes he held them with a claw and tore them into smaller bits. If he didn’t want something, like the green beans, he said, “Nuh,” meaning “No.” It was an emphatic “Nuh”—short, and decisive. His voice had a slightly nasal and digitized quality, but it was also tinny and sweet, like the voice of a cartoon character. It made you smile.

Under Pepperberg’s patient tutelage, Alex had learned how to use his vocal tract to imitate about one hundred English words, including the sounds for all of the foods she offered him, although he called an apple a “ban-erry.”

“Apples may 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 also 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 certain sounds than I ever imagined.”

Alex was also learning to say “brown.” As a kind of learning aid for “brown,” Pepperberg placed a small wooden block painted chocolate brown next to Alex.

After breakfast, Alex preened again, keeping an eye on the flock. Every so often, he used his claw to pick up the toy block and held it aloft as if showing it to everyone in the room. Then he opened his beak: “Tell me what co-lor?”

“Brown, Alex. The color is brown,” Pepperberg, Levin, and the other assistant replied in a kind of singsong unison. They stretched out brown into almost full two syllables, emphasizing the “br” and “own.”

Alex listened silently. Sometimes he tried part of the word: “rrr … own.” Other times, he again held up his block and repeated his question: “What co-lor?” And the trio of humans replied together: “Brown, Alex. The color is brown.”

Then Alex switched to the number seven: “Ssse … none.”

“That’s good, Alex,” Pepperberg said. “Seven. The number is seven.”

“Sse … none! Se … none!”

“He’s practicing,” she explained, when I asked what Alex was doing. “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.”

It sounded a bit mad, the idea of a bird willingly engaging in lessons and learning. But after listening to and watching Alex, I found it difficult to argue with Pepperberg’s explanation for his behaviors. She wasn’t handing him treats for the repetitious work or rapping him on the claws to make him say the sounds.

“He has to hear the words over and over before he can correctly imitate them,” Pepperberg said, after she and her assistants had pronounced “seven” for Alex a good dozen times in a row. “I’m not trying to see if Alex can learn a human language,” she added. “That’s not really the point. My plan always was to use his imitative skills to get a better understanding of avian cognition.”

In other words, because Alex was able to produce a close approximation of the sounds of some English words, Pepperberg could ask him questions about a bird’s basic understanding of the world. She couldn’t ask him what he was thinking about, because that was beyond his vocabulary, but she could ask him about his understanding of numbers, shapes, and colors. To demonstrate, Pepperberg carried Alex on her arm to a tall wooden perch in the middle of the room. She then retrieved a green key and a small green cup from a basket on a shelf. She held up the two items to Alex’s eye.

“What’s same?” she asked. She looked at Alex nose-to-beak.

Without hesitation, Alex’s beak opened: “Co-lor.”

“What’s different?” Pepperberg asked.

“Shape,” Alex said. Since he lacked lips and only slightly opened his beak to reply, the words seemed to come from the air around him, as if a ventriloquist were speaking. But the words—and what can only be called the thoughts—were entirely his.

Prior to Pepperberg’s study, scientists believed that birds could not learn to label objects. Assigning labels to items was something that only humans could do, linguists such as Noam Chomsky had argued in the 1960s. Scientists were also certain that birds could not understand concepts such as “same” and “different,” or “bigger” and “smaller.” Yet for the next twenty minutes, Alex ran through his tests, uttering the labels for a range of items (key, cup, paper) and distinguishing colors, shapes, sizes, and materials (wool versus wood versus metal) of various objects. The concept of “same/different” is considered cognitively demanding. It required Alex to pay attention to the attributes of the two objects and to understand exactly what Pepperberg was asking him to compare—their color, shape, or material. He had to make a mental judgment and then vocally give her the answer, using the correct label.

Next, she and Alex moved on to some simple arithmetic, such as counting the yellow toy blocks among a pile of mixed hues. Animals’ ability to count is a much debated subject, but Alex seemed able to do this (and Pepperberg had published several papers attesting to his skill). He even understood the concept of zero, or none, as he called it—again, the only animal, other than two chimpanzees, so far known with this ability.

And, then, as if to offer final proof of the mind inside his bird brain, Alex spoke up. “Talk clearly!” he commanded, when one of the younger birds Pepperberg was teaching mispronounced the word green. “Talk clearly!”

“Don’t be a smart aleck,” Pepperberg said, shaking her head at him. “He knows all this, and he gets bored, so he interrupts the others, or he gives the wrong answer just to be obstinate. At this stage, he’s like a teenage son; he’s moody, and I’m never sure what he’ll do.”

“Wanna go tree,” Alex said in a tiny voice.

Alex had lived his entire life in captivity, but he knew that beyond the lab’s door there was a hallway and a tall window framing a leafy elm tree. He liked to see the tree, so Pepperberg put her hand out for him to climb aboard. She walked him down the hall into the tree’s green light.

“Good boy! Good birdie,” Alex said, bobbing on her hand.

“Yes, you’re a good boy. You’re a good birdie.” And she kissed his feathered head.

DID ALEX UNDERSTAND what he was saying? From what I saw and heard, it seemed that he did. Watching him work was certainly amusing (it was hard to stop smiling at the sound of his voice) and also deeply perplexing (what’s really going on here?). Pepperberg understood my bafflement—she’d encountered it numerous times. Most of us, after all, have never met an educated parrot.

“Yes, he understands what he’s saying,” Pepperberg said in response to my question. She had published statistical studies that proved this.

When Alex asked about the color of his toy block, Pepperberg said, he was “asking for information.” And to figure out the number of yellow blocks there were on the tray, he had to stop and “actually count” the blocks. His ability to understand the concepts of same and different showed he could handle abstract thought as well. These are all higher-level cognitive skills, the kind of mental talents that prior to Alex most scientists thought only certain mammals—humans and possibly apes—could manage. He could even handle tasks beyond the capabilities of primates, such as understanding something about phonemes. Once when Pepperberg ignored his request for a nut, he finally sounded out the word for her: “Want a nut. Nnn … uh … tuh.”

Alex’s skills, though, made perfect sense to Pepperberg. Like the great apes (and humans), parrots have long lives and are members of complex societies. And like primates, these birds must keep track of changing relationships and environments.

“They need to be able to distinguish colors to know when a fruit is ripe or unripe,” Pepperberg said. “They need to categorize things—what’s edible, what isn’t—and to know the shapes of predators. And it helps to have a concept of numbers if you need to keep track of your flock and to recognize the various repetitions of a call. For a long-lived bird, you can’t do all of this with instinct; cognition must be involved.”

In other words, parrots aren’t born with brains that contain nothing but preprogrammed neurons; they must learn about their world, including how to live in a society. They must consider their actions and know how to evaluate the relationships of the other parrots in their flock.

As for his ability to enunciate the phonemes of “nut,” Pepperberg said that too made sense because parrots must discriminate among the calls of all their fellow parrots. A flock of parrots squawking together may sound like cacophony to our ears, but it is not just noise to the parrots.

For most of Alex’s life, other scientists were unsure what to make of Pepperberg’s study. Many thought she must be giving Alex hints, even if inadvertently, to speak or solve problems, and dismissed her research. They thought that Alex must be the latest version of Clever Hans, a horse that had duped the experts. In the early 1900s in Germany, Clever Hans became a vaudeville sensation by answering questions about numbers by tapping his hoof. His owner unknowingly tilted his head slightly when Hans reached the correct number. It was only a fraction-of-an-inch tilt, but Clever Hans always spotted it—while a committee of thirteen eminent scientists who investigated the horse’s mathematical talents did not. Eventually, a young experimental psychologist detected the owner’s unintentional cues. Hans was indeed clever, but not because he could do math.

Pepperberg had fought against her Clever Hans skeptics by making her videotapes of her sessions with Alex available, but ultimately she realized she would likely never convince them. Critics complained, too, that her study really involved only one bird, and what could possibly be concluded from a sample size of one? She had hoped that her trio of parrots would silence some of these complaints, but Griffin and Arthur are not the fast learners that Alex was (possibly because they have to share the attention of trainers, whereas Alex was an “only” parrot for fifteen years). And now Alex is gone, leaving her with but two parrots, neither of which seems to be a superstar.

This is not to say that all scientists dismissed Pepperberg’s studies. Many others—from strict ornithologists to comparative psychologists—found her method of communicating with Alex, and what she’d learned about his mind, to be remarkable, particularly his ability to understand abstract concepts. They regretted that Alex had died so young, and at a time when birds’ cognitive abilities were finally being recognized.

“Alex was an extraordinary parrot,” said Alex Kacelnik, a behavioral ecologist at Oxford University, who was researching New Caledonian crows. “He opened the door for many of us to start thinking about birds in a new way.”

Kacelnik had started his New Caledonian crow study in the late 1990s. When I visited him in 2006, he had twenty-three birds in his aviary, all but four of them caught in the forests of that South Pacific island. Although crows, like parrots, are good mimics, it wasn’t their communication skills that intrigued Kacelnik but their talent as skilled toolmakers and users. In the wild, they sculpt a variety of probes and hooks from twigs and leaves to poke into rotting logs and the crowns of palm trees, where fat grubs hide. Like hunters armed with spears or arrows, the crows also carry their tools with them when out on foraging expeditions.

To show me how the crows use tools, Kacelnik and I stepped inside the aviary with a young, captive-born female named Uek (pronounced Weck). She was housed in a large enclosure made of wire fencing, with indoor and outdoor areas, tree limbs for climbing, and sticks, leaves, and kids’ toys to investigate. Uek looked like a standard, glossy black crow. She was perched on one of the stumps but immediately flew to the ground when we stepped inside.

Kacelnik spoke to her softly, “Hello, Uek. We have a visitor.”

Uek cocked her head and looked up at us, but then her attention reverted to ground level—and my running shoes. Kacelnik had told me that Uek loved to explore the seams in people’s shoes. So I wasn’t completely surprised when she picked up a twig about the diameter of a barbecue skewer and hopped toward me. She held the twig at an angle in her beak and deftly poked it along the seams of my left running shoe, searching for something tasty. When that proved grubless, she hopped to my right shoe and tried again. No luck there either. She was so adept with her stick—her manner reminded me of an efficient, pen-wielding secretary—that I was sorry I didn’t have any resident shoe grubs.

Uek was the daughter of Kacelnik’s most famous crow, Betty. Betty had recently died from an infection. But in the year before her death she had stunned Kacelnik and his colleagues by inventing a new tool during a test they’d given her. Kacelnik closed the aviary door, and we walked upstairs to his office, where he played a video of Betty making her discovery. In the film, Betty flies into a small room. She’s glossy black like her daughter, with a crow’s bright, inquisitive eyes, and she immediately spies the test before her on a plastic tray: a glass tube with a tiny basket lodged in its center. The basket holds a bit of meat. The scientists have placed two pieces of wire in the room. One is bent into a hook, the other is straight. They figure Betty will choose the hook to lift the basket by its handle.

But experiments don’t always go according to plan. Another crow steals the hook before Betty can find it. Betty is undeterred. She looks at the meat in the basket and then spots the straight piece of wire. She picks it up with her beak and pushes one end into a crack in the tray. She then grasps the other end of the wire with her beak, and pulls it sideways—causing the end inserted into the crack to bend into a hook. Thus armed, she lifts the basket out of the tube.

“This was the first time Betty had ever been in this situation,” Kacelnik said. “But she knew she could use it to make a hook and exactly where she needed to bend it to make the size she needed.”

Kacelnik had given Betty other tests, each requiring a slightly different solution, such as making a hook out of a flat piece of aluminum rather than a wire. Each time, Betty invented a new tool and solved the problem. “It means she had a mental representation of what it was she wanted to make. Now that,” Kacelnik said, “is a major kind of cognitive sophistication.”

Scientists were astonished in the 1960s when Jane Goodall first reported her discovery that chimpanzees make tools. At the time, toolmaking was thought to be one of the key differences separating humans and animals. As amazing as her report was, it also seemed to make sense: chimpanzees and humans share a common ancestor that used tools. But our last common ancestor with birds was a reptile that lived about three hundred million years ago. How can we explain the discovery of these ingenious behaviors in creatures so far removed from our evolutionary lineage?

“This is not a trivial matter,” Kacelnik said. “It means that evolution can invent similar forms of advanced intelligence more than once—that it is not something reserved only for primates or mammals.” In other words, creativity and inventiveness, like other forms of intelligence, are not limited to the human line.

Kacelnik had published his discovery of Betty’s inventiveness in Science in 2002. His was one of a growing number of studies that helped dismantle the notion that birds lack brains—a bias that stemmed from the research of the German neurobiologist Ludwig Edinger, the founder of comparative anatomy. In the late nineteenth century, Edinger dissected the brains of fish, amphibians, reptiles, birds, and mammals, noting the differences and similarities. He thought the various brains had evolved in a linear, progressive fashion, one building on the basic layers of the other, like the geological strata of a mountain. Humans, with the most layered brains, were at the peak. To Edinger, the mammalian cerebral cortex—that massive outer layer with its multiple folds of “gray matter”—was the site of all higher intelligence. Made up of a six-deep layer of cells, the cerebral cortex sits atop older, more “primitive” brain structures, such as the basal ganglia. Edinger thought that animals without a neocortex—meaning invertebrates, fish, amphibians, reptiles, and birds—could not possibly be intelligent or have any thoughts. His idea persisted throughout much of the twentieth century. As late as 1977—the year that Pepperberg acquired Alex—the comparative anatomist Alfred Romer wrote that the brains of birds were dominated by their “basal nuclei” and thus were “essentially … highly complex mechanism[s] with little learning capacity.”

But, as with fish, anatomists had simply misinterpreted the way that the brains of birds (and amphibians and reptiles) are organized. By the 1990s, anatomists realized that all vertebrate brains consist of the same basic parts (a hindbrain, midbrain, and forebrain) and that there are structures in the brains of birds, fish, and amphibians that are homologous to the mammalian cortex. Finally, in 2004, after spending several years reevaluating the anatomy of avian brains, a team of international experts officially declared that birds do have the neural anatomy for thought.

No longer hampered by Edinger’s bias, scientists in recent years have discovered a remarkable variety of cognitive talents in birds: Clark’s nutcrackers have tremendous memories; they can hide up to thirty thousand seeds and find them six months later. Rooks, close relatives of crows, are highly inventive, making and using tools in captivity, even though they don’t do this in the wild. Magpies and parrots have a sophisticated understanding of the physical world. At a very young age, they realize that when an object disappears behind a curtain it has not vanished—an ability that children also develop as toddlers. Magpies can recognize themselves in a mirror as well, an ability that suggests they are self-aware. Crows and pigeons can recognize and discriminate among human faces; pigeons can also distinguish between cubist and impressionistic styles of painting. One group of birds—bowerbirds, which live in Australia and on the island of New Guinea—even have an artistic sensibility, the only animal in which this has ever been discovered. Greater bowerbirds, for instance, use the illusion of perspective (the method an artist uses to make objects in a painting look far away) when arranging piles of progressively smaller bits of glass and stone in front of their bowers, structures they build of twigs and decorate to attract females for mating. And Kacelnik and others studying the New Caledonian crows have now shown that these crows are able to use various tools in the correct sequence and in the wild may have tool technology cultures that are distinct from one region on the island to another.

Some birds are also psychologically savvy. Western scrub jays understand that sometimes other jays are likely up to no good. The jays stash numerous nuts and seeds for the winter, just as nutcrackers do. If they can, jays will steal each other’s caches, too. So a smart scrub jay that sees another jay watching him hide his nut will return later, alone, and hide the nut elsewhere.

“It means that scrub jays have something akin to ‘theory of mind,’ ” said Nicola Clayton, a Cambridge University comparative psychologist who together with her husband and fellow researcher, Nathan Emery, discovered that jays possess this talent. “It seems that they understand what the other bird is thinking.” Clayton and Emery have also shown that scrub jays not only know where they’ve stashed their nuts and grubs but when they did so—and will return sooner to retrieve “fresh foods,” like grubs, before they spoil. So clever and innovative are jays, rooks, and crows that Emery dubbed them “feathered apes.” (Clayton and Emery aren’t simply besotted bird lovers. On one visit to their aviary lab, just outside Cambridge, England, Emery showed me the new experiments he and his students had devised to test rooks’ knowledge of physics. Faced with a nut floating in a glass tube partially filled with water, would the rook know to pick up stones lying nearby and drop them into the tube to raise the water level—and the nut—to within reach of its beak? Yes!—the rook easily accomplished this and other demanding feats, including using tools in sequence, as do the New Caledonian crows. “They are much brighter than people give them credit for,” Emery said, as we started back to Cambridge in his car. But as soon as we turned onto the main highway, a ring-necked pheasant broke from the hedgerow and dashed into the road. Emery slammed on the brakes, barely missing the pheasant. “Now there’s a stupid bird,” Emery said, shaking his head. “How many generations does it take before they learn about cars?”)

Many birds surpass apes as communicators and possess vocal capabilities eerily akin to those of humans. Parrots, hummingbirds, and a variety of songbirds share with humans a talent for vocal learning: hearing a sound, copying it, then reproducing it. It’s what Alex was doing when he was practicing the words brown and seven. Vocal-learning birds have specific genes and specialized parts of their brain for song learning, as humans do for speech. And like human infants, young songbirds have a babbling phase and learn their songs by listening to and imitating adult tutors. They also dream about new songs they’re learning, replaying them in their minds, something scientists discovered by comparing the brain activities of zebra finches as they sang during the day and slept at night.^† Songbirds that don’t have an adult model to listen to will end up singing incorrectly, just as human infants with hearing disorders have difficulties speaking as adults.

Among mammals, vocal learning has so far been found only in whales, dolphins, elephants, seals, and bats. Other animals produce innate songs and calls; dogs and cats, for instance, cannot learn to bark or meow in a new way. These species are called auditory learners; sounds can have meaning to them, but they respond with only limited vocalizations.

In humans, vocal learning becomes more difficult after puberty, which is why adults find it challenging to learn foreign languages, although we never lose the talent completely. Some birds, such as zebra finches, learn their songs as chicks and sing these same ones for life. But a few, including mockingbirds and parrots, are lifelong vocal learners like us—and so may offer the very best models for studying this talent.

It’s still a mystery as to why vocal learning evolved in such a diverse group of animals. Each group—from parrots to dolphins to humans—apparently developed it independently, just as flying evolved separately in birds and bats. But it’s not an unsolvable mystery, says Erich Jarvis, a neurobiologist at Duke University, who led the 2004 reexamination of avian brains. Physiologically, he thinks, vocal learning stems from a common neural pathway for controlling motor behaviors. Behaviorally, it’s surely connected to sex, he believes—to the drive to find a mating partner. “Of the species that produce learned song, all of them will do it in mating interactions, including humans.”

Vocal learners often have a sense of rhythm, too, but auditory learners don’t. Alex liked to bob his head to the beat of disco music from the 1980s. Snowball, a sulphur-crested cockatoo, became a YouTube sensation for his head-bobbing and Rockette dance-kicking routine to the Backstreet Boys’ tune “Everybody … Rock Your Body.” In their rhythmic displays, we readily recognize ourselves—and we don’t think for a minute that either we or they are doing something mindless when tapping our toes to the music.

DURING MY VISIT with Alex, he noticed when his fellow parrots were slacking off during a lesson. Then he would shout at them, “On the tray! On the tray!”—because Pepperberg held up things for them to look at on a small, round tray. It was his way of saying, “Pay attention!”—something that in hindsight many scientists now wish they had done more of while Alex was alive.

As a young bird, Alex had suffered from a lung infection that may have left him in a weakened state but without any visible health problems. The evening before he died, he exchanged his usual good-byes with Pepperberg, telling her as she turned out the lights, “You be good. I love you.”

“I love you, too,” she replied.

“You’ll be in tomorrow?”

“Yes,” Pepperberg said, “I’ll be in tomorrow.”

That night Alex’s heart gave out; a lab technician found him lying on the bottom of his cage in the morning. He wrapped Alex in a cloth and took him to the chief veterinarian at Brandeis, who placed his body in a walk-in cooler. Later, Pepperberg and her lab manager, Levin-Rowe, tucked his cloth-wrapped body into a carrier and drove him to the clinic of his regular veterinarian. Pepperberg chose not to view Alex, who over the years had become so much more to her than a colleague. He had been her friend. She wanted to remember Alex like that, as her buddy, a pal “full of life and mischief,” amazing the world of science, “doing so many things he was not supposed to do.” Through her tears, she whispered only “Good-bye, little friend,” then turned and left the clinic.

Most African grays live into their fifties. Alex was only thirty-one—and he died only three years after the brains of birds were finally discovered. Could we have learned more from him if scientists had not been blinded by the bird-brain bias? Certainly, he offered us the potential for insights into the minds of animals in a way no other creature ever has. “Clearly, animals know more than we think and think a great deal more than we know. That essentially … is what Alex taught us,” Pepperberg wrote after Alex died.

Still, Alex was a captive bird, raised by and with humans. And that left me wondering, what do parrots do in the wild that requires so much thought? Pepperberg had suggested some reasons, such as their need to distinguish among fruits and to keep track of the various relationships in their flocks. But Alex’s mental abilities hinted at the possibility that parrots are capable of much more. To find out, I tracked down Karl Berg, an ornithologist at Cornell University (now at the University of California in Berkeley). He invited me to Venezuela to listen to his green-rumped parrotlets talk—not to the humans—but to one another.

* This is a very condensed version of Pepperberg’s actual model/rival technique. There are many other subtle steps in the entire process, which Pepperberg describes in her 1999 book, The Alex Studies.

† Songbirds also generate new brain nerve cells throughout their lives—a finding that led human neurologists to take a fresh look at our own brains. Until recently, neurologists believed that adult human brains were “fixed,” incapable of adding new neurons. But in 1983, S. A. Goldman and Fernando Nottebohm showed that canaries readily sprout fresh neurons as they learn new songs. Their discovery sparked a paradigm shift and led to an entirely new field of science: neurogenesis, or the study of how the adult brain generates new brain cells, something that (happily) we humans, too, are capable of throughout our lives—although, apparently, we don’t do it quite as well as do birds.