The Bird Way: A New Look at How Birds Talk, Work, Play, Parent, and Think

by Jennifer Ackerman

There are some rules, he told me. Three in particular: Males are flashier than females, which are often a dull color so that they blend in with their surroundings while they’re incubating eggs. Adults are more colorful than youngsters. Birds are brighter in the breeding season.

Three in particular: Males are flashier than females, which are often a dull color so that they blend in with their surroundings while they’re incubating eggs. Adults are more colorful than youngsters. Birds are brighter in the breeding season.

In a handful of other species, females sport brighter, fancier plumage than males. These include phalaropes, spotted sandpipers, painted snipes, wattled jacanas, and button quail. But in each of these cases, there is a reversal of usual sex roles, with males incubating eggs and females defending territories and fighting among themselves for access to males. “So these species are really the exceptions that prove the rule because they demonstrate that the competitive sex is the one most likely to have bright colors,” says Heinsohn.

lance-tailed manakin’s tightly choreographed cooperative display of two males performing fluttering, twitching somersaults to woo females. Only one of the males, the alpha, gets to mate; the beta male is always relegated to the role of wingman, and yet time after time, he pours his heart into his best possible performance.

Australia is where some fundamental aspects of bird being were born. Like song.

the first scale of intelligence for birds, based on a bird’s behavior in the wild. How inventive is the species in its natural environment? Does it make use of new things and find creative solutions to the problems it faces? Does it try new foods? These activities are indicators of what’s called behavioral flexibility, which is one fairly reliable measure of intelligence. It’s the ability to do something new—to change your behavior to address new circumstances and new challenges.

A recent, more high-tech instance of bird ingenuity popped up in 2018 when a scientist tracking western gulls with geolocators to see where they fed was puzzled to see a gull traveling at sixty miles per hour for a distance of seventy-five miles, crossing the Bay Bridge from San Francisco to Oakland and traveling along the interstates before returning by the same route to her nest. It turned out that the gull, a female breeding on the Farallon Islands west of San Francisco Bay, had hitched a ride on a garbage truck bound for an organic composting facility in the Central Valley near Modesto. At first the researcher thought the bird might have gotten trapped in the truck. But then, two days later, the same thing happened. Clearly, this gull was using its head (if not its palate—as one Bay Area news reporter quipped, “It might be the only time a San Francisco resident ever drove to Modesto for dinner”).

recent, more high-tech instance of bird ingenuity popped up in 2018 when a scientist tracking western gulls with geolocators to see where they fed was puzzled to see a gull traveling at sixty miles per hour for a distance of seventy-five miles, crossing the Bay Bridge from San Francisco to Oakland and traveling along the interstates before returning by the same route to her nest. It turned out that the gull, a female breeding on the Farallon Islands west of San Francisco Bay, had hitched a ride on a garbage truck bound for an organic composting facility in the Central Valley near Modesto. At first the researcher thought the bird might have gotten trapped in the truck. But then, two days later, the same thing happened. Clearly, this gull was using its head (if not its palate—as one Bay Area news reporter quipped, “It might be the only time a San Francisco resident ever drove to Modesto for dinner”).

birds have higher neuron counts in their small brains than do mammals or even primates of similar brain size. Neurons in bird brains are much smaller, more numerous, and more densely packed than those in mammalian and primate brains. This tight arrangement of neurons makes for efficient high-speed sensory and nervous systems. In other words, say the researchers, bird brains have the potential to provide much higher cognitive clout per pound than do mammalian brains.

Birds have shown us a different way to shape an intelligent brain. Mammals use larger neurons to connect distant brain regions; birds keep their neurons small, close together, and locally connected and grow only a limited number of larger neurons to handle long-distance communication. In building powerful brains, says Herculano-Houzel, nature has two strategies: It can tinker with the number of neurons and their size, and also, it can change their distribution in different parts of the brain. In birds, nature uses both tactics—to brilliant effect.

Why are these surprising insights turning up now? For one thing, scientists are shedding biases that have blinkered research for generations. Sensory prejudices, for instance—the notion that the world we humans see, hear, and smell is the world experienced by other creatures. In fact, it’s strictly our reality, constrained by our cognitive, biological, even cultural limitations. Other animals experience other realities.

Then there’s geographic bias. We thought we had a handle on the bird way of doing things based on bird behavior in the Northern Hemisphere, primarily northern North America and Europe. That’s where most ornithologists were working until quite recently.

so. Birds in temperate regions, it turns out, are often the exceptions rather than the rule. Many of their habits and behaviors are typical primarily of birds with a short breeding season and birds that migrate—a relatively new development from an evolutionary standpoint.

Breakthroughs have also come from the study of wild cognition, the sophisticated ways birds learn and solve problems in their natural settings. Not long ago, scientists largely limited their study of bird cognition to the laboratory, where they had strict control over any testing conditions that might affect a bird’s performance—sights, sounds, smells, lighting, temperature, the presence of other birds, as well as the bird’s internal state, its hunger, and its prior experience.

While some birds like pigeons and zebra finches are naturals in the lab, unfazed by human-made environments and devices, others don’t take well to an artificial setting and don’t reveal their true capacities in an experimental setup. Test the memory of a coal or marsh tit with a touchscreen computer in a lab, and it performs miserably, holding in mind an image for at most a few minutes—whereas in the field, it can remember the locations of individual food caches for months.

Time and again we humans have claimed that we’re the only species with a particular capacity—toolmaking, reasoning, language-like communication—only to discover that birds share similar abilities.

Sandhill cranes intentionally paint their own feathers, using tufts of muddy grass to daub them with iron-rich red mud, possibly for camouflage or to repel insects. Other birds, such as herons, pelicans, and ibis, use so-called cosmetic coloration for sexual signaling.

Birds are the great communicators of the animal world. They talk while they court and while they fight, while they forage and while they travel, while they stave off predators and while they raise their young. They speak with their voices, their bodies, and their feathers. They may not have the facial musculature we primates use to express ourselves, but they can powerfully communicate their inner states with head and body, with facial feathers, crests, gestures, displays of wings and tail, as sandhill cranes do.

So the quelea form little neighborhoods surrounded by familiar birds, individuals they know will stick to their own nest and not try to steal from them. A newly arrived, unfamiliar male poses a bigger threat than a familiar neighbor going about his own nest building. It’s called the “dear enemy effect.” The birds get to know their neighbors very quickly. One quelea signals its identity to another by flashing its face, making it easy for the neighbor to quickly learn who it is. “Once that’s settled,” says Dale, “everyone can stop harassing each another and get down to the business of nest building.” As it turns out, it’s the quelea’s bright red bill that signals quality, embedded in their colorful feathers of identity. Imagine all that information, all that messaging, contained in a bird’s face. But really, should we be surprised? Recognizing individuals is the foundation for social relationships, and queleas are highly social creatures.

But more important than body mass is eye size. Scientists in the UK found that birds with larger eyes and greater visual capability at low light sing earlier than others—true in neotropical habitats, too.

Butcherbirds are the Sweeney Todds of the bird world. They do dastardly deeds—skewering small birds and other animals for dinner—but they sing like seraphim, sometimes in trios. So spectacular and haunting is this bird’s song that violinist and composer Hollis Taylor worked for a decade recording it and transforming it into music.

Science is just beginning to parse the complexity and meaning of bird vocalizations. Even common species such as American robins make more than twenty different types of sounds, most of which remain mysterious in purpose.

The vocalizations of most songbird species differ from place to place, forming local “dialects” just like human accents, distinct and long-lasting regional and cultural differences in the structure and composition of songs. These dialects play a role in courtship—females of some species prefer males with songs that include syllables from their own song vocabulary—and also, in resolving territorial disputes, allowing birds to distinguish between local and foreign individuals and settle conflicts without fighting.

The voice box of birds is a structure called a syrinx, buried deep in a bird’s chest cavity. Sound emerges when the membranes of the syrinx vibrate, shifting the flow of air through the organ. The syrinx in birds varies from the bulbous resonance chambers and long looping trachea of ducks, geese, and swans—up to twenty times the expected length—which produce sound that exaggerates their body size, to the tiny pair of chambers in songbirds, controlled by delicate syringeal muscles. Some songbirds have such fine control over the multiple muscles in both sides of their syrinx that they can produce different sounds at the same time, in essence, singing a duet with themselves.

When zebra finch parents are breeding in a hot climate, and the nest hits a temperature above 80 degrees Fahrenheit, they’ll chirp the news to their unborn chicks in the last third of the incubation period—the moment when the embryos are developing their temperature-regulation system. In response to these “hot calls,” the chicks will actually curtail their growth and emerge smaller—an adaptive advantage in the heat.

One bell miner is a delight to hear. And for a minute or two, a colony of forty pinging away is wondrous, as if stars could talk. But then the chorus starts to irritate, like ringing in the ears or the plink, plink, plink of a dripping faucet. Unlike North American birds, where territorial calling is seasonal, these birds start pinging at dawn and go right through to dusk every day of the year. “It’s one of the world’s most constant, pervasive animal sounds,” says Tim Low. “The miners are saying, ‘Stay out; if you come into the colony, you’ll get attacked.’”

male and female singing in a call-and-response so precisely timed and seamlessly delivered it sounds like one bird calling. The male initiates the call, and the female responds within a fraction of a millisecond. Why would a bird bother with such a highly choreographed saraband of sound? There’s a female-biased sex ratio in this population—fewer male than female whipbirds—so there’s actually competition between females for males, explains Naomi Langmore, who studies bird behavior at Australian National University in Canberra. A female whipbird may use the duet to defend her exclusive position in a partnership with the male. It’s called mate guarding, and it’s an unusual strategy for female birds.

“Migrants have a very different pattern of territoriality and pairing than in the tropics. Typically, the male will arrive on the breeding grounds singing his head off, and the females will fly in and listen, and they’ll plunk down on the chosen male’s territory. Then they’ll have a very short breeding season. They just go for it like crazy, and then they leave.” Resident birds, on the other hand, like those in the tropics, have to defend their territory all year long. If, over the years, a partner dies, the remaining bird has to be able to defend that territory and attract a new mate. “And there can be divorce, as well,” says Langmore. “Whichever bird is left has to be able to sing to defend its territory or attract a new mate. So it seems like it’s quite a recent thing that females have lost song in these migratory groups.”

bucolic.

McLachlan has found that the honeyeater’s alarm calls are not in fact simple cries of warning, but a complex language rich with meaning. “These birds really go extreme, with up to ninety-six elements in a single call,”

“The theory was that the bigger your eye, the more light is let in, the brighter the world seems and the earlier you sing,” says McLachlan. Despite the “very annoying sombre greenbul—which was our massive outlier and despite its big eyes always started last in every chorus”—the pair did find the expected correlation.

“Life as a small bird is like being a human in Jurassic Park,” he says. “You’re constantly on edge, constantly wary of what can eat you, including hawks ten or twenty times your size.” No wonder birds have evolved numerous strategies for raising alarm. Magrath and his students have found that some birds signal danger with just their wings. Crested pigeons have specially modified wing feathers that produce distinct notes during escape from predators, prompting other birds to flee. Sometimes the warning isn’t a sound at all but the silence between sounds. When noisy, social birds like red-winged blackbirds suddenly get quiet, it’s a strong signal there’s danger nearby. But most birds call out vocal warnings.

These were mobbing calls—abrupt, short, loud, and repetitive—alarm calls made in response to predators that are not moving at high speed and so are not an immediate or intense threat—usually a terrestrial predator like a snake or cat or, in this case, a perching bird. The call alerts other birds and signals them to fly toward the source of the call and join in with their own mobbing calls, or attack or mob the predator to drive it away. “There’s a predator here! Come help me harass it!”

High-pitched flee, or aerial, alarm calls, on the other hand, usually mean there’s a predator in flight, which is a lot more dangerous for a bird. These calls are typically in a narrow bandwidth, with a lot of up-and-down amplitude, making the sounds harder to locate, especially for raptors with relatively poor hearing in that frequency range. Small birds use flee alarm calls to alert other birds to imminent danger from above, signaling them to freeze or take immediate cover, while not boosting their own chances of being snatched by a predator. Flee alarm calls send birds away from a threat; mobbing calls bring them toward it.

Crows are among the most frequent mobbers, swooping and dashing down on a hawk from above and behind it, always keeping the menace in sight. Gulls often resort to the practice, too, with an unusual twist: vomiting on the predator with keen aim. Colonies of fieldfares fire from another orifice, ejecting feces on a predator in such volume and with such accuracy that the threatening creature is literally grounded or stopped in its tracks. If enough of these droppings-bombs hit their target, they can soak a bird’s wings so it can’t fly.

The classic experiment demonstrating that birds can learn about threats from fellow birds was conducted by German zoologist Eberhard Curio. Curio showed that European blackbirds learned to regard a harmless bird as a predator by observing other birds mobbing it. He put one “teacher” blackbird in a box and showed it a species that was a real threat—a model of a little owl—which evoked a powerful mobbing response in the teacher bird. At the same moment, he showed another blackbird—the “observer,” or student—a model of a bird that’s harmless to blackbirds, a noisy friarbird. The student bird could see both the teacher and the friarbird but not the little owl. Almost instantly, it learned to fear, and mob, the friarbird. Remarkably, Curio showed that this recognition and fear of an enemy could be culturally transmitted from bird to bird, along a chain of up to six individuals. Bird number six in the string mobbed the friarbird with a ferocity equal to the original teacher bird—a superb example of social learning.

“This categorization of threats into those that are flying and those that are on the ground seems to be a pretty common strategy among birds,”

The tit’s jar call causes the birds to search for snakes and to become more visually responsive to any object resembling a snake. It was the first evidence that a non-human animal could visualize something referred to in a vocalization.

In white-browed scrubwrens and fairy-wrens, the number of notes encode information about how far away a predator is. The chickadee-dee-dee mobbing alarm calls of black-capped chickadees contain messages—coded in the number of dees at the end of the call—about the size of a predator and hence, the degree of threat it represents. More dees means a smaller, more dangerous predator. A great horned owl, too big and clumsy to pose much of a risk to the tiny chickadee, elicits only a few dees, while a small, agile bird of prey such as a merlin or a northern pygmy owl may draw a long string of up to twelve dees. When I first learned this about the chickadee, it changed the way I heard all birds. What I’d taken as random chirps were in fact sophisticated signals to other birds, tweets of intelligence.

I step out of my door here on campus and do a playback to the fairy-wrens, they understand what’s going on and flee. And if I walk five minutes up the road to the botanic gardens and do the playback, the fairy-wrens don’t respond. To me, this is very startling. It means the fairy-wrens do not respond to unfamiliar alarm calls until they learn that they mean danger—in effect, until they learn the new language.” Learning, rather than familiar acoustic structure, determines a bird’s response.

Igic and McLachlan managed to repeat the training process of throwing the glider while playing the sound eight times to ten fairy-wrens, and the fairy-wrens mastered the new vocabulary in just two days. Says Magrath, “I remember Jess and Brani bursting through the door, saying, “It worked!” Before the training, the fairy-wrens ignored the novel sound, but after training, they fled to cover just from playback of the new alarm sound, without the presence of the model sparrowhawk. Wild birds had succeeded in learning a new language.

The superb lyrebird seems a modest bird, coppery brown and pheasant-like, until it raises its tail or opens its throat. Spectacular tail feathers shaped like a lyre—two long, curved, outer feathers forming the arms, a set of white filamentous feathers, the strings—give the bird its common name. But its voice is what makes it truly superb. The lyrebird sings like no other bird, a fantastic blend of its own calls and songs and dozens of perfectly mimicked sounds, brilliant imitations of other bird voices in the forest,

yes. it equating this to evolved mimicry is a bit like rejecting evolution if you stop and unpack the logic of choosing to do something vs selection

Birds that cache their food, such as scrub jays, will move their food stashes several times if they know they’re being watched by another jay, shifting it to different locations or even fake-moving it but leaving it buried, a shell game aimed at confusing the viewer.

The blue jay’s ability to imitate a hawk is so good that I’ve often looked skyward vainly searching for a red-tailed hawk wheeling above, when the source of the hawk’s keening call is a blue jay in the nearby understory.

Mimicry was once chalked off as mindless behavior, a belief reflected in our verb to parrot, with its overtones of mechanical repetition without appreciation of meaning. Now we know it’s anything but. Imitating a song or call requires vocal learning—listening closely, memorizing, recalling, and practicing—trying repeatedly to produce a perfect imitation of what is remembered and making corrections until the copy is a match.

Dalziell thinks that young male lyrebirds, like mockingbirds, learn most of their mimicked calls from older adult males rather than directly from the species they imitate. “Their mimicry seems to be in the fashion of other males in the area,” she says. “There’s less variation within a population and more variation between populations.”

He dances to only four types of songs, says Dalziell, and each song type is accompanied by its own moves. “He’ll coordinate his song and dance so that each different song has a unique choreography.”

“For lyrebirds, the evidence is strong that mimicry in males is sexually selected.” Belting out mimicry to females he can’t see is a male’s way of advertising himself, saying, “Look how clever I am, how accurate and versatile my mimicry is, how strong is my voice. I’m very intelligent (the accuracy of my mimicry shows that I have a good brain), and I can sing for hours a day.” As Dalziell points out, the female alone sees to all the parental care—building the nest, brooding and raising the chick, defending her feeding territory. All she needs from a male is sperm. A choosy female measures a prospective mate by his spectacular plumage, his dancing ability, and his loud, complex, flamboyant song, including the versatility and accuracy of his mimicry and the carrying capacity of his calls. All of these traits may act as “honest” signals of a male’s quality—his ability to learn, his strength and vigor, his genes, the conditions in which he was raised. “It’s probably good for females to mate with males that are proficient vocal mimics so that their offspring are also competent at using mimicry to defend nests if they’re female and to obtain mates if they’re male,” says Dalziell. A female will listen to various males for months and months before she settles on a mate. Only the best performers get to pass on their genes. Hence, a smart, high-performing bird species gets smarter, better at mimicking, at dancing, and at growing gorgeous tail feathers.

There are reports of blue jays mimicking not just red-tailed hawks, but raptors of all kinds, causing grackles and other birds to drop their food and flee, whereupon the jays seize the free meal.