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

by Jennifer Ackerman

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.

Hummingbirds, for instance. Anyone who has met these little birds knows they’re extreme, a ton of truculence packed into a feathered fraction of an ounce. Fiercely territorial, they behave like Chihuahuas that think they’re mastiffs. There’s good evidence that, in some settings at least, they act like sociopaths.

“Extreme behavior in birds is more likely in Australia than anywhere else.” Australian birds occupy more ecological niches than birds anywhere on earth. They tend to be longer lived and more intelligent than birds on other continents. Also, Australia is where some fundamental aspects of bird being were born. Like song.

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.

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.

In a laboratory setting, pigeons can remember hundreds of images for longer than a year. And because of their ability to make subtle visual distinctions, they have even been trained to detect the difference between normal and cancerous tissue in mammograms—with more accuracy than a trained technician.

Zebra finch parents can tell their young while they’re still developing in the egg that it’s hot outside. This is vital information for a growing chick. In hot climates, birds need to be able to lose heat, which is easier with a smaller body. 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.

Alarms calls are a prime example. Not only are they functionally referential—working like words do to describe the characteristics of an object—but according to a few recent studies, they may also show some key linguistic features of human language. Compositional syntax, for instance, the set of rules for arranging and combining sound and words to create meaningful phrases and sentences. In language, it matters how we order our words—and how we combine them to form more complex messages. In English, watch out makes sense; out watch does not. We thought only humans used syntax in this way. But Toshitaka Suzuki has found that Japanese tits seem to use these sorts of linguistic rules in their alarm calls. The tits have a repertoire of eleven different notes, which they use alone or in combination with other notes, resulting in more than 175 different call types, and listening tits respond accordingly.

Suzuki created a call that these birds had never heard before—an artificial sequence that combined their own ABC alert call with the tää recruitment call of another species, a willow tit. When he played the combination calls, the Japanese tits decoded the meaning of the ABC-tää combination, but not when it was played in reverse. This suggests that the birds are not just memorizing complex signals but rather applying a generalized grammatical ordering rule to decode messages.

When you lie, you understand that your message is false, and that the recipient of the lie will believe your falsehood. That means understanding that your belief differs from theirs, that they have a mind with knowledge that differs from your own—a capacity known as theory of mind.

And here’s the creepy part: Kapoor suspects that a newcomer “mimic male” may attempt to usurp an established male’s territory by attacking and killing him and then taking his place—if he himself is not killed in the process. This is still just a hypothesis, yet to be observed, but Kapoor has seen brutal fights that lasted a week or more, with the birds trying to stab each other with specialized sharp tips on their bills. If a young mimic male is successful, “thereafter, he would likely be treated by the other birds in the lek as if he were actually Fred, their local neighbor, and tolerated as the rightful owner of his territory,” he says. “The other territory holders wouldn’t know the difference because his mimicry is sufficiently well practiced to fool them.”

Birds top us in color vision, too. They see hues beyond our imagining. Humans have three types of color-receptive cones in our retinas, blue, green, and red. Birds have a fourth color cone that is sensitive to ultraviolet wavelengths. We are thus “trichromatic,” and most diurnal birds are “tetrachromatic.”

A sensitivity to DMS also explains why seabirds consume plastics and other trash. Plastic debris emits the chemical scent, making trash smell like food and creating a kind of olfactory booby trap for seabirds.

The experiment found that the crows could hold in mind the type and location of tools that were out of their sight while planning a sequence of tool-using behaviors. This “preplanning,” using mental trial and error, is a key component of human foresight—the ability to form a mental plan before beginning to execute it.

ethno-ornithology—the study of the relationship between birds and people.

Most birds have no penis. But there are exceptions. Several species of ducks, geese, and swans have an organ like a human penis, which is inserted into the female.

They gain nothing from the venture of picking out a male but genes—no material benefits or protection, no companionship or help with parenting. Just sperm.

transmogrifying

Transform in a magical manner.

There’s a theoretical model suggesting why this is so. Bird parents “imprint” on the chicks that hatch from the eggs in their very first clutch, and after that, reject any chick that’s different. Host parents that are unlucky enough to be parasitized in their first clutch will imprint on the cuckoo chick and rebuff their own young forever after. The high cost of mistakenly imprinting on a cuckoo nestling should prevent host birds from evolving the ability to reject chicks.

In fact, most Australian host species tended not to reject cuckoo eggs. “Which is completely counter to evolutionary theory,” she says.

In Australia, not only do the hosts break the rules, so do the cuckoo chicks. “Because of this good recognition ability in hosts, cuckoo chicks have evolved wonderful mimicry of host young, either in appearance or in begging calls, which you don’t get anywhere else.” The bronze-cuckoos, which target fairy-wrens, thornbills, and gerygones, she says, “have evolved these fantastically matching chicks that mimic the size, the skin color, the down color, even the mouth color of the host species.”

Now we know that 9 percent of bird species breed cooperatively and share parental care, more than nine hundred species, including acorn woodpeckers, Florida scrub jays, western bluebirds, and many of Australia’s little bands of fairy-wrens. Most cooperative breeders are “facultative,” meaning they can breed successfully without helpers. Relatively few, like the ani, are “obligate”—they require helpers at the nest in order to successfully fledge young.

greater anis are rebels. Here is a bird that seems to prefer long-term living and nesting with strangers. This is the first mystery: Why would birds join up with unrelated birds to accomplish something as vital as raising their young?

In the nonbreeding season, they form huge communal roosts of a hundred birds or so. But in the rainy season, when it’s time to raise their young, they coalesce into tight-knit groups of two to four unrelated, socially monogamous pairs, plus a couple of nonbreeding helpers. Together each group builds a shared nest in which all of the females collectively lay their eggs more or less synchronously. They all share parenting care, raising the mixed clutch of young until they fledge. The groups are extraordinarily stable, says Riehl, often staying together a decade or more.

Scientists have found that social living in animals actually changes the brain, enhancing the neural mechanisms underlying cognition—the synthesis and release of neuromodulators, the formation and strengthening of synapses between neurons, the birth of new neurons. Group living demands a lot of cognitive skills, including learning, memory, perhaps even the ability to take another bird’s perspective.

It’s what I love about birds. They’re as inconsistent and unpredictable, as varied, as any group of animals on earth.

Birds live and act on a spectrum, just as we do, and they prove the power of exceptions, both in defining rules and in breaking them.

We understand now that birds are not just biologically distinct but culturally distinct—and that this is true even within a species. Birds learn styles of singing, bower building, playing that vary from one place, one population, to another. Palm cockatoos, kea, kelp gulls, great tits, superb fairy-wrens, and superb lyrebirds have taught us that birds use social learning to master different methods of foraging, to grasp the identity of their enemies, to master the dialect of their region or their own distinctive drumbeat. Clearly there is no one way to be a bird, just as there is no one way to be a human.

With climate change, shrinking habitats, extinction of species, the analogy may become even more pertinent. When I think about what we are doing to our fellow travelers on this planet, to the planet itself, I feel a wave of despair. Just before his death in 2009, the world’s leading expert on species associated with army ants, Carl Rettenmeyer, completed the first comprehensive list of animals known to keep company with Eciton burchellii, the “mini-lion” of neotropical forests. Rettenmeyer recorded 557 species in consort with the ants, ranging from mites and insects to a huge variety of birds. It’s the largest group of animals ever described centering on a single species. At least 300 of these species depend on the ants, including the charismatic ocellated antbird. The disappearance of Eciton burchellii from any habitat over their vast range would trigger the extinction of hundreds of birds and other animals.