March 08, 2008
"Bird brain" no longer a put-down
It's not just birds that have gotten a bum rap and a moniker -- "Bird Brain" -- as a result of humans being too dense to see how smart they really are. An article in the new issue of National Geographic takes a fascinating look at a bunch of animals that have been unfairly labeled as being dumb as a stump.
Take for instance sheep; their very species is used to describe easily led, idiotic voters: Sheeple. The movie Babe even played against expectations back in the '90s, showing sheep to be aware and resentful of their reputations for being the barnyard 'tards.
Now, researchers have found that sheep recognize faces -- 30 sheep and 10 humans -- and remember what individuals look like for as long as two years.
But Alex the parrot blew my mind.
Alex, an African Grey Parrot, not only had a huge vocabulary, he could count, understand colors, shapes and sizes -- and even understood the concept of zero.
[Researcher Irene] 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 almost one hundred English words, including the sounds for all of these foods, although he calls an apple a "banerry."
"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.
[...]
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."
It sounded a bit mad, the idea of a bird having lessons to practice, and willingly doing it. But after listening to and watching Alex, it was 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 pronouncing "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 never been 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, but she could ask him about his knowledge 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.
Without hesitation, Alex's beak opened: "Co-lor."
"What's different?" Pepperberg asked.
"Shape," Alex said. His voice had the digitized sound of a cartoon character. Since parrots lack lips (another reason it was difficult for Alex to pronounce some sounds, such as ba), 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.
For the next 20 minutes, Alex ran through his tests, distinguishing colors, shapes, sizes, and materials (wool versus wood versus metal). He did some simple arithmetic, such as counting the yellow toy blocks among a pile of mixed hues.
And, then, as if to offer final proof of the mind inside his bird's brain, Alex spoke up. "Talk clearly!" he commanded, when one of the younger birds Pepperberg was also 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.
He was a good birdie until the end, and Pepperberg was happy to report that when he died he had finally mastered "seven."
Betsy, a Border Collie from Austria, understands more than 300 words -- and learns new ones faster than primates. And human toddlers.
Just how easily new mental skills can evolve is perhaps best illustrated by dogs. Most owners talk to their dogs and expect them to understand. But this canine talent wasn't fully appreciated until a border collie named Rico appeared on a German TV game show in 2001. Rico knew the names of some 200 toys and acquired the names of new ones with ease.Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig heard about Rico and arranged a meeting with him and his owners. That led to a scientific report revealing Rico's uncanny language ability: He could learn and remember words as quickly as a toddler. Other scientists had shown that two-year-old children—who acquire around ten new words a day—have an innate set of principles that guides this task. The ability is seen as one of the key building blocks in language acquisition. The Max Planck scientists suspect that the same principles guide Rico's word learning, and that the technique he uses for learning words is identical to that of humans.
To find more examples, the scientists read all the letters from hundreds of people claiming that their dogs had Rico's talent. In fact, only two—both border collies—had comparable skills. One of them—the researchers call her Betsy—has a vocabulary of more than 300 words.
"Even our closest relatives, the great apes, can't do what Betsy can do—hear a word only once or twice and know that the acoustic pattern stands for something," said Juliane Kaminski, a cognitive psychologist who worked with Rico and is now studying Betsy. She and her colleague Sebastian Tempelmann had come to Betsy's home in Vienna to give her a fresh battery of tests. Kaminski petted Betsy, while Tempelmann set up a video camera.
[...]
Betsy's owner—whose pseudonym is Schaefer—summoned Betsy, who obediently stretched out at Schaefer's feet, eyes fixed on her face. Whenever Schaefer spoke, Betsy attentively cocked her head from side to side.
Kaminski handed Schaefer a stack of color photographs and asked her to choose one. Each image depicted a dog's toy against a white background—toys Betsy had never seen before. They weren't actual toys; they were only images of toys. Could Betsy connect a two-dimensional picture to a three-dimensional object?
Schaefer held up a picture of a fuzzy, rainbow-colored Frisbee and urged Betsy to find it. Betsy studied the photograph and Schaefer's face, then ran into the kitchen, where the Frisbee was placed among three other toys and photographs of each toy. Betsy brought either the Frisbee or the photograph of the Frisbee to Schaefer every time.
"It wouldn't have been wrong if she'd just brought the photograph," Kaminski said. "But I think Betsy can use a picture, without a name, to find an object. Still, it will take many more tests to prove this."
Uek, a New Caledonian Crow, has a relative who is impressing researchers at Oxford University with her ability to not only use but make tools for specific tasks, an ability scientists believed was limited to primates.
"People were surprised to discover that chimpanzees make tools," said Alex Kacelnik, a behavioral ecologist at Oxford University, referring to the straws and sticks chimpanzees shape to pull termites from their nests. "But people also thought, 'Well, they share our ancestry—of course they're smart.' Now we're finding these kinds of exceptional behaviors in some species of birds. But we don't have a recently shared ancestry with birds. Their evolutionary history is very different; our last common ancestor with all birds was a reptile that lived over 300 million years ago.
"This is not trivial," Kacelnik continued. "It means that evolution can invent similar forms of advanced intelligence more than once—that it's not something reserved only for primates or mammals."
Kacelnik and his colleagues are studying one of these smart species, the New Caledonian crow, which lives in the forests of that Pacific island. New Caledonian crows are among the most skilled of tool-making and tool-using birds, forming probes and hooks from sticks and leaf stems to poke into the crowns of the palm trees, where fat grubs hide. Since these birds, like chimpanzees, make and use tools, researchers can look for similarities in the evolutionary processes that shaped their brains. Something about the environments of both species favored the evolution of tool-making neural powers.
But is their use of tools rigid and limited, or can they be inventive? Do they have what researchers call mental flexibility? Chimpanzees certainly do. In the wild, a chimpanzee may use four sticks of different sizes to extract the honey from a bee's nest. And in captivity, they can figure out how to position several boxes so they can retrieve a banana hanging from a rope.
Answering that question for New Caledonian crows—extremely shy birds—wasn't easy. Even after years of observing them in the wild, researchers couldn't determine if the birds' ability was innate, or if they learned to make and use their tools by watching one another. If it was a genetically inherited skill, could they, like the chimps, use their talent in different, creative ways?
To find out, Kacelnik and his students brought 23 crows of varying ages (all but one caught in the wild) to the aviary in his Oxford lab and let them mate. Four hatchlings were raised in captivity, and all were carefully kept away from the adults, so they had no opportunity to be taught about tools. Yet soon after they fledged, all picked up sticks to probe busily into cracks and shaped different materials into tools. "So we know that at least the bases of tool use are inherited," Kacelnik said. "And now the question is, what else can they do with tools?"
Plenty. In his office, Kacelnik played a video of a test he'd done with one of the wild-caught crows, Betty, who had died recently from an infection. In the film, Betty flies into a room. She's a glossy-black bird with a crow's bright, inquisitive eyes, and she immediately spies the test before her: a glass tube with a tiny basket lodged in its center. The basket holds a bit of meat. The scientists had placed two pieces of wire in the room. One was bent into a hook, the other was straight. They figured Betty would choose the hook to lift the basket by its handle.
But experiments don't always go according to plan. Another crow had stolen the hook before Betty could find it. Betty is undeterred. She looks at the meat in the basket, then spots the straight piece of wire. She picks it up with her beak, pushes one end into a crack in the floor, and uses her beak to bend the other end into a hook. Thus armed, she lifts the basket out of the tube.
"This was the first time Betty had ever seen a piece of wire like this," 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."
They gave 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."
The article has many more photos of surprisingly smart critters, like the octopus who liked squirting researchers and the bonobo who makes tools and may be talking (just too fast and high-pitched for us to understand).
And check out the mouse that recognizes when it doesn't know the right answer.
A tremendously interesting article, and a subject that's fascinated me since childhood. Read the whole thing.
Posted by Mike Lief at March 8, 2008 10:32 PM
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