The Genius of Birds - Softcover

JENNIFER ACKERMAN has been writing about science, nature, and human biology for almost three decades. Her most recent books include Sex Sleep Eat Drink Dream: A Day in the Life of Your Body; Ah-Choo: The Uncommon Life of Your Common Cold; Chance in the House of Fate: A Natural History of Heredity; and Notes from the Shore. A contributor to Scientific American, National Geographic, The New York Times, and many other publications, Ackerman is the recipient of a National Endowment for the Arts Literature Fellowship in Nonfiction, a Bunting Fellowship, and a grant from the Alfred P. Sloan Foundation.

Introduction
 
THE GENIUS OF BIRDS
 
For a long time, the knock on birds was that they’re stupid. Beady eyed and nut brained. Reptiles with wings. Pigeon heads. Tur- keys. They fly into windows, peck at their reflections, buzz into
power lines, blunder into extinction.
Our language reflects our disrespect. Something worthless or un- appealing is “for the birds.” An ineffectual politician is a “lame duck.” To “lay an egg” is to flub a performance. To be “henpecked” is to be ha- rassed with persistent nagging. “Eating crow” is eating humble pie. The expression “bird brain,” for a stupid, foolish, or scatterbrained person, en- tered the English language in the early 1920s because people thought of birds as mere flying, pecking automatons, with brains so small they had no capacity for thought at all.
That view is a gone goose. In the past two decades or so, from fields and laboratories around the world have flowed examples of bird species capable of mental feats comparable to those found in primates. There’s a kind of bird that creates colorful designs out of berries, bits of glass, and blossoms to attract females, and another kind that hides up to thirty- three thousand seeds scattered over dozens of square miles and remem- bers where it put them months later. There’s a species that solves a classic puzzle at nearly the same pace as a five-year-old child, and one that’s an expert at picking locks. There are birds that can count and do simple math, make their own tools, move to the beat of music, comprehend basic prin- ciples of physics, remember the past, and plan for the future.
In the past, other animals have gotten all the publicity for their near- human cleverness. Chimps make stick spears to hunt smaller primates and dolphins communicate in a complex system of whistles and clicks. Great apes console one another and elephants mourn the loss of their own.
Now birds have joined the party. A flood of new research has over- turned the old views, and people are finally starting to accept that birds are far more intelligent than we ever imagined—in some ways closer to our primate relatives than to their reptilian ones.

Beginning in the 1980s, the charming and cunning African grey par- rot named Alex partnered with scientist Irene Pepperberg to show the world that some birds appear to have intellectual abilities rivaling those of primates. Before Alex died suddenly at the age of thirty-one (half his expected life span), he had mastered a vocabulary of hundreds of English labels for objects, colors, and shapes. He understood the categories of same and different in number, color, and shape. He could look at a tray holding an array of objects of various colors and materials and say how many there were of a certain type. “How many green keys?” Pepperberg would ask, displaying several green and orange keys and corks. Eight out of ten times, Alex got it right. He could use numbers to answer questions about addition. Among his greatest triumphs, says Pepperberg, were his knowledge of abstract concepts, including a zerolike concept; his capacity to figure out the meaning of a number label from its position in the num- ber line; and his ability to sound out words the way a child does: “N-U-T.” Until Alex, we thought we were alone in our use of words, or almost alone. Alex could not only comprehend words, he could use them to talk back with cogency, intelligence, and perhaps even feeling. His final words to Pepperberg as she put him back in his cage the night before he died were his daily refrain: “You be good, see you tomorrow. I love you.”

In the 1990s, reports began to roll in from New Caledonia, a small is- land in the South Pacific, of crows that fashion their own tools in the wild and appear to transmit local styles of toolmaking from one genera- tion to the next—a feat reminiscent of human culture and proof that so- phisticated tool skills do not require a primate brain.

When scientists presented these crows with puzzles to test their problem-solving abilities, the birds astonished them with their crafty solutions. In 2002, Alex Kacelnik and his colleagues at Oxford University “asked” a captive New Caledonian crow named Betty, “Can you get the food that’s out of reach in a little bucket at the bottom of this tube?” Betty blew away the experimenters by spontaneously bending a piece of wire into a hook tool to pull up the little bucket.
Among the published studies tumbling from scientific journals are some with titles that lift the brows: “Have we met before? Pigeons recog- nize familiar human faces”; “The syntax of gargles in the chickadee”; “Language discrimination by Java sparrows”; “Chicks like consonant music”; “Personality differences explain leadership in barnacle geese”; and “Pigeons on par with primates in numerical competence.”
 
Bird brain: The slur came from the belief that birds had brains so diminutive they had to be devoted only to instinctual behavior. The avian brain had no cortex like ours, where all the “smart” stuff happens. Birds had minimal noggins for good reason, we thought: to allow for airborne ways; to defy gravity; to hover, arabesque, dive, soar for days on end, migrate thousands of miles, and maneuver in tight spaces. For their mas- tery of air, it seemed, birds paid a heavy cognitive penalty.
A closer look has taught us otherwise. Birds do indeed have brains very different from our own—and no wonder. Humans and birds have been evolving independently for a very long time, since our last com- mon ancestor more than 300 million years ago. But some birds, in fact, have relatively large brains for their body size, just as we do. Moreover, when it comes to brainpower, size seems to matter less than the number of neurons, where they’re located, and how they’re connected. And some bird brains, it turns out, pack very high numbers of neurons where it counts, with densities akin to those found in primates, and links and con- nections much like ours. This may go a long way toward explaining why certain birds have such sophisticated cognitive abilities.
Like our brains, the brains of birds are lateralized; they have “sides” that process different kinds of information. They also have the ability to replace old brain cells with new ones just when they’re needed most. And although avian brains are organized in an entirely different way from our brains, they share similar genes and neural circuits, and are capable of feats of quite extraordinary mental power. To wit: Magpies can recog- nize their own image in a mirror, a grasp of “self” once thought limited to humans, great apes, elephants, and dolphins and linked to highly devel- oped social understanding. Western scrub jays use Machiavellian tactics to hide their food caches from other jays—but only if they’ve stolen food themselves. These birds seem to have a rudimentary ability to know what other birds are “thinking” and, perhaps, to grasp their perspective. They can also remember what kind of food they buried in a particular place— and when—so they can retrieve the morsel before it spoils. This ability to remember the what, where, and when of an event, called episodic mem- ory, suggests to some scientists the possibility that these jays may be able to travel back into the past in their own minds—a key component of the kind of mental time travel once vaunted as uniquely human.

News has arrived that songbirds learn their songs the way we learn languages and pass these tunes along in rich cultural traditions that began tens of millions of years ago, when our primate ancestors were still scut- tling about on all fours. Some birds are born Euclideans, capable of using geometric clues and landmarks to orient themselves in three-dimensional space, navigate through unknown territory, and locate hidden treasures. Others are born accountants. In 2015 researchers found that newborn chicks spatially “map” numbers from left to right, as most humans do (left means less; right means more). This suggests that birds share with us a left-to-right orientation system—a cognitive strategy that underlies our human capac- ity for higher mathematics. Baby birds can also understand proportion and can learn to choose a target from an array of objects on the basis of its ordinal position (third, eighth, ninth). They can do simple arithmetic, as well, such as addition and subtraction. Bird brains may be little, but it’s plain they punch well above their weight.
 
Birds have never seemed dumb to me. In fact, few other creatures appear so alert, so alive in fiber and faculty, so endowed with perpetual oomph. Sure, I’ve heard the story of the raven attempting to crack open a Ping-Pong ball, presumably to get at an egglike morsel within. A friend of mine, while vacationing in Switzerland, watched a peacock try to fan its broad tail during a mistral. It toppled over, stood upright again, fanned again, and tipped over again, six or seven times in a row. Each spring the robins nesting in our cherry tree attack the side mirror of our car as if it were a rival, pecking furiously at their own reflections while streaking the door with guano.
But who among us hasn’t been toppled by our own vanity or made an enemy of our own image?
I’ve watched birds most of my life and have always admired their pluck and focus and the taut, quick vitality that seems almost too much for their tiny bodies to contain. As Louis Halle once wrote, “A man would be worn out in short order by such intensity of living.” The common species I saw around my old neighborhood appeared to negotiate the world with brisk curiosity and aplomb. The American crows striding around our garbage cans with a prince’s proprietary air looked like highly resourceful creatures. I once watched a crow stack two crackers in the middle of a road before flying off to a safe spot to devour his collected booty.

One year, an eastern screech owl roosted in a box on a maple tree just a few yards from my kitchen window. In the daylight hours, the owl slept, only its round head showing, perfectly framed in the round hole facing the window. But at night, the owl was gone from the box, off hunting in the night. As the dawn light rose, there were signs of his brilliant success— the wing of a mourning dove or songbird hanging from the hole of the box, twitching, twitching, before it was yanked inside.
Even the red knots I encountered on the beaches of Delaware Bay, not the mentally swiftest of birds, seemed to know where to be—and when— to catch the rich feast of eggs laid by horseshoe crabs each full moon in spring. What calendar of sky drew these birds northward and told them where to go?
 
I learned about birds from a pair of Bills. The first was my father, Bill Gorham, who began taking me birdwatching near our home in Wash- ington, D.C., when I was seven or eight. It was the Beltway version of a Swedish gökotta—the act of rising early to appreciate nature—and it was one of the palpable joys of my childhood. On early weekend mornings in spring we left the house in the dark and headed to the woods along the Potomac River to catch the dawn chorus, that mysterious moment when birds sing with a thousand voices in “A Music numerous as space— / But neighboring as Noon,” as Emily Dickinson wrote.

My father learned about birds as a Boy Scout from a nearly blind man named Apollo Taleporos. The old man relied on his ears alone to pick up species. Parula warbler. Yellow-rumped warbler. Towhee. “The birds are there!” he would call out to the boys. “Go find them!” My father got very good at identifying birds by their calls—the melodious flutelike song of the wood thrush, the soft whichity, whichity of a common yellowthroat, or the clear whistling call of a white-throated sparrow.
As my father and I wandered through the woods in late starlight, I would listen to the husky song of a Carolina wren and wonder what, if anything, those birds were saying, and how they learned their songs. Once, I encountered a young white-crowned sparrow apparently engaged in song practice. There he was, perched invisibly somewhere in a low branch of a cedar tree, softly running through his whistles and trills, getting them wrong, and then going back over them quietly and persistently until he delivered the final run of his kind. This sparrow, I later learned, gleans his songs not from his own father but from birds in his natal environment, that very neighborhood of woods and rivers where my father and I rambled—a place with its own dialect passed down through the generations.
The other Bill I met at the Sussex Bird Club when I lived in Lewes, Delaware. Bill Frech was up and out of the house every morning at five a.m. for four or five hours of watching shorebirds and those little brown jobs, or LBJs, common in the woods and fields around Lewes. A patient, devoted, and inexhaustible observer, he kept meticulous notes on what birds he saw, where, and when, which ended up at the Delmarva Orni- thological Society as part of the state’s official bird records. This Bill was nearly deaf, but he was a wizard at identifying birds visually, by their so-called GISS, their general impression, size, and shape. He showed me how to spot a goldfinch high on the wing by its dipping flight and how to tell shorebirds apart by noting their personality, behavior, and gestalt, just as one recognizes friends from a distance by their overall manner and gait. He taught me the difference between casual “birdwatching” and the more intense, focused “birding,” and urged me to go beyond identifying birds to noting their actions and behavior.

The birds I observed on those excursions and others seemed to know what they were doing. Like the black-billed cuckoo a friend saw perched just above a nest of tent caterpillars: The cuckoo waited as the caterpillars climbed out of the nest to scale the tree, then plucked them off one at a time, like sushi from a conveyor belt.Still, I never imagined that the magpies and jays, the chickadees and herons, I admired so much for their feathers and flight, their songs and calls, might have mental abilities that match—even exceed—those in my primate tribe. How can creatures with a nut-sized brain perform such sophisticated mental feats? What has shaped their intelligence? Is it the same or differ- ent from ours? What, if anything, do their little brains have to tell us about our big ones?
Intelligence is a slippery concept, even in our own species, tricky to define and tricky to measure. One psychologist describes it as “the capac- ity to learn or to profit by experience.” And another, as “the capacity to acquire capacity”—the same sort of circular definition offered up by Har- vard psychologist Edwin Boring: “Intelligence is what is measured by in- telligence tests.” As Robert Sternberg, a former dean at Tufts University, once quipped, “There seem to be almost as many definitions of intelli- gence as . . . experts asked to define it.”

In judging the overall intelligence of animals, scientists may look at how successful they are at surviving and reproducing in many different environments. By this measure, birds trump nearly all vertebrates, includ- ing fish, amphibians, reptiles, and mammals. They are the one form of wildlife visible nearly everywhere. T...