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

by Jennifer Ackerman

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.

Why mob if it’s so dangerous? It’s a good way to expose a predator and to drive it off, especially when young are at risk. It’s also a way to impress on inexperienced birds a predator’s dangerous nature, offering so-called teacher benefits. A naïve bird watching other birds mob a threat teaches that bird to fear it, too, and to either avoid it or mob it more strongly, creating more knowledgeable informants and mobbers. There’s strength in numbers.

“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,” says McLachlan.

Alarm calls may also encode what a predator is doing.

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.

More notes means a greater menace. This rule holds true across species and calling contexts and even continents. It makes sense. With a long string of notes you get your message across and also reduce the risk of false alarms. Think about what would happen with the opposite system: If a one-note call meant big danger, birds would flee at the start of what could well be a longer, less urgent call, resulting in a lot of wasted energy.

It makes sense that birds are quick studies, good at gleaning lessons from a single experience, especially where danger is concerned. They can’t afford to forget. As behavioral ecologists have drily noted, “Few failures . . . are as unforgiving as the failure to avoid a predator: being killed greatly decreases future fitness.”

The question of why mockingbirds mimic certain birds (Carolina wrens, tufted titmice, blue jays, cardinals) and not others (mourning doves and chipping sparrows) may shed light on the lyrebird’s selective mimicry. The mockingbird mimics only those songs similar in pitch and rhythm to its own vocalizations. It may be physically unable to replicate certain features of other species’ songs, such as smoothly coordinated switches from one side of the syrinx to the other or jumps in the frequencies of notes. This may be true of lyrebirds, too.

Birds not only mimic to impress potential mates. Mounting research suggests they also appropriate calls and songs to deceive and manipulate others for their own profit. For instance, to steal a free lunch.

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.

Like humans, birds will go to great lengths to get a good meal. They have figured out how to dig up invisible food, crack open its armor, discard its poisonous or unpalatable parts, and fish it out of hidden places with specially crafted tools. They’ve learned how to process impossible amounts of spatial information to remember where food is, manipulate their prey, even detect food through senses we thought they didn’t have.

you knew when the place was active by the volt of vultures across the road hunching awkwardly on the rooftops, sunken heads rounding into curved shoulders. Today they still jostle for space near the site, like a Supreme Court made of Richard Nixons.

But as most of us now know, turkey vultures have gotten a bad rap. The truth is, those naked heads relieved of adornment are extremely hygienic—gory stuff just doesn’t stick. And it’s a lie that vultures particularly relish a ripe, rotting mess. They actually prefer fresher carrion. As such, they perform a vital, and vastly underrated, service to the environment: the quick, competent cleanup and recycling of dead creatures.

What happens when vultures vanish, people learned the hard way in India and Pakistan more than a decade ago. There, a mass die-off of old-world vultures caused by an arthritis drug in the flesh of dead cattle led to an eruption of rabies. Dogs took over feeding on the carcasses, and the canine population exploded, along with the spread of the deadly disease.

Indeed, for a long time, most birds were considered merely “a wing guided by an eye.” Foraging was a matter of instinct and visual searching out of sustenance—whether in the form of flitting insects, skittering rodents, fresh roadkill, or tasty and nutritious fruits, nuts, and berries. This bias toward vision is hardly surprising. We humans are eye-minded creatures, and when it comes to visual acuity, we’re near the top of the animal chart. It makes sense that for a long time, studies of food searching in birds focused on sight. The world of birds, we thought, was a world like ours, of light, color, and movement, the twitch of a rodent or the whirl of flies circling a carcass.

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.” With their extra UV cone, birds can distinguish shades of color we can’t tell apart, allowing them to spot prey well camouflaged against the uniform background of a grassy field or leafy forest floor, and to detect things invisible to us—like the trail of urine left by a vole.

most owls listen for their food.

If you think about where owls are hunting, the natural conditions they face, the Blakiston’s reliance on vision and the great gray owl’s reliance on hearing make sense, says Jonathan Slaght. Great gray owls hunt where it’s flat, with snow and quiet. Fish owls regularly hunt in narrow river valleys, with shallow, fast-flowing, and rocky waterways. “If a fish owl had hypersensitive hearing and hunted in these waterways, it would go crazy,” he says.

Stager also identified the specific scent that drew vultures to carrion. The discovery arose from a serendipitous conversation with field engineers at an oil company, who had been aware for some time that turkey vultures have knowing noses, and used the birds to locate leaks in natural gas lines. The engineers had figured out that if they introduced ethyl mercaptan into the line, they could locate leaks by the concentrations of turkey vultures circling above the line or sitting on the ground next to it.

Thanks to Stager’s experiments, we now know that turkey vultures are highly attracted to the scent and can use it to find a target as tiny as a dead vole buried in leaves on the forest floor beneath a thick canopy of trees.

Wenzel found that every bird she tested could detect odors—pigeons, quail, hummingbirds, robins, even house finches and starlings. It turns out that European starlings use odor to discriminate between plant species during the nesting season,

seabirds—known as the “fish of the air”

Fish, of course, being known as the “birds of the ocean”.

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.

Clayton and her colleagues showed that scrub jays have a powerful ability to remember the past and use this information to plan for the future. Scrub jays manage to recall not only where they buried their food, but also what they buried in a particular spot and when they buried it there so that they can retrieve first those foods that are quick to spoil, like fresh fruit, insects and worms, and save for later those that are more enduring, like nuts and seeds.

The memory skills of caching jays and bivouac-checking antbirds may pale compared with the sophisticated human ability to mentally wander forward and backward in time. But who knows? Maybe that especially juicy cricket picked up at an outstanding ant swarm is an antbird’s version of the proverbial Proustian madeleine dipped in tea.

Of course, there’s a proximate explanation for why ravens play, says Osvath: Because it’s fun. “We scientists are not supposed to say that, but almost every one of us—between the papers, so to speak—would agree that the animals we see playing are having fun, and that fun can be its own powerful reward.”

Thank you! I don't see why we need any further explanation, but I'm not an academic ornithologist.

One unfortunate Scottish tourist at the same site lost a wad of cash when a kea snatched it from his dashboard. What’s cool about this, says Schwing, is that it happened after New Zealand had switched over to plastic money, which doesn’t deteriorate. “You can’t even rip it,” he says. “So somewhere in the mountains, twelve hundred New Zealand dollars are lining the most gangster kea nest in the world.”

“The moment we give the adult kea access to a young bird, the males almost fight with one another to see who gets to feed these unknown, unrelated birds. The first day the fledglings arrive in the group, they’re overwhelmed with food. They start beating their wings to get rid of the adults because they just can’t swallow any more food.”

Footage from video cameras captured images of several young male kea pushing the cones around and repositioning them, sometimes leaving the cones in the middle of the highway just outside the tunnel. The birds might just be having a little fun, says Taylor, but there also may be method to their madness. When the cars slow to avoid the cones, the kea come to the windows to investigate and poke around for food and toys.