Introduction When You''ve Seen One Bird There is the mammal way and there is the bird way." This is one scientist''s pithy distinction between mammal brains and bird brains: two ways to make a highly intelligent mind. But the bird way is much more than a unique pattern of brain wiring. It''s flight and egg and feathers and song. It''s the demure plumage of a mountain thornbill and the extravagant tail feathers of an Indian paradise flycatcher, the solo song of a superb lyrebird and the perfectly timed duets of canebrake wrens, an osprey''s hurtling dive toward the sea, and a long-legged heron''s still, patient eyeing of the dark water. There is clearly no single bird way of being but rather a staggering array of species with different looks and lifestyles. In every respect, in plumage, form, song, flight, niche, and behavior, birds vary. It''s what we love about them.

Diversity fascinates biologists. It fascinates birdwatchers, too, driving us to assemble life lists, to travel to far corners of the globe to visit a rare species or jump in the car to spot a vagrant blown in by a storm, to go "pishing" and whistling into the woods to draw that elusive warbler. Watch birds for a while, and you see that different species do even the most mundane things in radically different ways. We give a nod to this variety in expressions we use to describe our own extreme behaviors. We are owls or larks, swans or ugly ducklings, hawks or doves, good eggs or bad eggs. We snipe and grouse and cajole, a word that comes from the French root meaning "chatter like a jay." We are dodos or chickens or popinjays or proud as peacocks. We are stool pigeons and sitting ducks.

Culture vultures. Vulture capitalists. Lovebirds. An albatross around the neck. Off on a wild goose chase. Cuckoo. We are naked as a jaybird or in full feather. Fully fledged, empty nesters, no spring chicken.

We are early birds, jailbirds, rare birds, odd birds. As biologist E. O. Wilson once said, when you have seen one bird, you have not seen them all. This is certainly true for behavior. Take white-winged choughs. Australians say it''s easy to fall in love with these birds-and it is. They''re adorable, charismatic, gregarious, comical: lined up on a narrow tree branch, six or seven red-eyed puffs of black feathers, tenderly preening one another in a pearl-like strand of endearment and affection.

Clumsy fliers, they prefer to walk everywhere, swaggering through dry eucalypt woodlands with their heads strutting backward and forward like a chicken''s. They pipe and whistle and wag their tails like puppies. They''re fond of playing follow-the-leader or keep-away, rolling over one another to win possession of a stick or a slip of bark. About the size of a crow but slimmer-black with elegant white wing patches and an arched bill-they live in stable groups of four to twenty birds and are always, always found in clusters or huddles or lines. Like a tight-knit family, they do everything together, drink, roost, dust bathe, play, run in wide formation like a football team to share a food discovery. Together they build big bizarre nests of mud (or emu or cattle dung if they''re in a pinch) set on a horizontal branch, queuing up on the limb, waiting their turn to add their bit of shredded bark, grass, or fur soaked with mud to the rim of the nest. Together they brood, guard, and feed the young. Members of family groups are rarely more than five or ten feet apart.

I once saw three fledglings jammed together on the ground like the three wise monkeys, see no evil, hear no evil, speak no evil. And yet there''s a darker side to choughs, especially if the weather turns bad. They squabble and fight, one group pitted against another. Larger groups gang up on smaller groups, flying at them and pecking viciously, dislodging eggs from nests, and nests from trees. They are known to go on violent crime sprees, ruining the nesting efforts of numerous other groups. One bird was observed picking up eggs in its bill one at a time and tossing them to the ground. Perhaps most unsettling, warring choughs do something few animals apart from humans and ants do: They forcibly kidnap and enslave the young from other groups. This is a book about the range of surprising and sometimes alarming behaviors that birds perform daily, activities that firmly, sometimes gleefully, reverse conventional notions about what is ÒnormalÓ in birds and what we thought they were capable of.

Lately, scientists have taken a new look at behaviors they have run past for years and dismissed as anomalies or set aside as abiding mysteries. What they have found is upending traditional views of how birds conduct their lives, how they communicate, forage, court, breed, survive. It''s also revealing the remarkable strategies and intelligence underlying these activities, abilities we once considered uniquely our own, or at least the sole domain of a few clever mammals-deception, manipulation, cheating, kidnapping, and infanticide, but also ingenious communication between species, cooperation, collaboration, altruism, culture, and play. Some of these extraordinary behaviors are conundrums that seem to push the edges of, well, birdness: a mother bird that kills her own infant sons, and another that selflessly tends to the young of other birds as if they were her own. Young birds that devote themselves to feeding their siblings, and others so competitive that they''ll stab their nest mates to death. Birds that create gorgeous works of art, and birds that wantonly destroy the creations of other birds. Birds like the white-winged chough that contain their own contradictions: one murderous bird that impales its prey on thorns or forked branches but sings so beautifully that composers have devised whole compositions around its songs; another with a reputation for solemnity that is strongly addicted to play; and another that collaborates with one species-humans-but parasitizes another in gruesome fashion. Birds that give gifts and birds that steal, that dance and drum, that paint their creations or paint themselves.

Birds that build walls of sound to keep out intruders, and birds that summon playmates with a special call-and may hold the secret to our own penchant for playfulness and the evolution of human laughter. Earth is home to well over ten thousand different species of birds, many with marvelous, often Seussian, names-the zigzag heron and white-bellied go-away bird, speckled mousebird and naked-faced spiderhunter, the Inaccessible Island rail, pale chanting goshawk, shining sunbeam, military macaw, and wandering tattler, a yellow-legged stanza of elegance I watched probe for crustaceans and worms on the fringes of a tiny island in AlaskaÕs Kachemak Bay. The wandering refers to its presence everywhere over vast stretches of sea. Tattler refers to the shrill tattling call to alert other birds if an observer approaches too closely. There are whydahs and widowbirds, fantails and fairy-wrens, broadbills and hornbills, and buff-breasted buttonquail (known as BBBQs). Birds live on every continent, in every habitat, even-like the burrowing owl and the Puerto Rican tody-underground. They run to extremes in everything from size and flight style to feather color and physiology. I once saw a biologist weigh a male broad-tailed hummingbird: one-seventh of an ounce.

Compare this with the cassowary, a giant weighing one hundred pounds-around twelve thousand times the hummer-that looks as much like a dinosaur as any living bird, can rise up six feet to pluck fruit from limbs, and is capable of killing a man. Or consider the ten-foot wingspan of an Andean condor relative to the five-inch span of a goldcrest. Some birds are agile fliers, like the northern goshawk, slalom king of the bird world, and swifts and hummingbirds, those avian acrobats. Big, flightless birds, such as the emu and the cassowary, don''t take wing at all, although their ancient ancestors did. Likewise, the Gal++pagos cormorant, used to have flight, but lost it over evolutionary time in favor of the grounded life. Seabirds such as the wandering albatross log tens of thousands of miles each year to return to tiny islands in the middle of vast oceans to breed. They may go for years without touching land and, when seas are rough, will sleep on the wing, one eye open to navigate. Bar-tailed godwits migrate from Alaska to New Zealand in a single 7,000-mile flight, traveling day and night for seven to nine days-the longest recorded nonstop migratory flight.

In terms of flying distance, the Arctic tern takes all, circling the world in orbit with the seasons. The bird flies from its breeding grounds in Greenland and Iceland to its wintering grounds in Antarctica-a round trip of almost 44,000 miles, the longest migration ever recorded. Over the thirty years of its life, a tern may fly about 1.5 million miles, the equivalent of three trips to the moon and back. As an astronaut who traveled to the International Space Station and made the first all-female space walk in 2019, Jessica Meir knows a thing or two about going to extremes. Meir''s goal had always been to walk in space, and on her way to that dream, she explored the lives of two birds capable of truly exceptional physiological feats-one that holds its breath for impossibly long periods of time, the other that flies at breathtaking altitudes. At Penguin Ranch in Antarctica, Meir investigated emperor penguins, the world''s best bird divers. These penguins can dive deeper and longer than any other bird and can tolerate extremely low levels of oxygen in their blood-far below those that would render a hum.