"Shaken by a Living Wind"

On the Manistee River banks, a Potawatomi tribal leader—Simon Pokagon —heard something strange and unnerving as he prepared his fishing traps. It was a bright spring morning in 1850 Michigan and except for a distant, mysterious rumble, all was clear and tranquil around the water. But the sound grew louder by the moment until finally the 20-year-old fisherman put down his traps and stopped dead in waders, frozen in fear. “An army of horses laden with sleigh bells was advancing through the deep forests towards me,” he wrote later about the experience.

“As I listened more carefully,” he continued in his recollection, “I concluded that instead of the tramping of horses, it was distant thunder; and yet, the morning was clear, calm, and beautiful.” As the weird, miraculous sound came nearer, he slowly realized what it was: “While I gazed in wonder and astonishment, I beheld moving toward me, in an unbroken front, millions of pigeons, the first I had seen that season.”

Alas, the environmental movement came too late to save the beloved passenger pigeon. Yet, there is no shortage of written accounts about the sense of wonderment the birds evoked in its onlookers. If you have any doubt about the tragedy of its extinction, you must only read some of these accounts to see what a special and irreplaceable bird it was. Young Pokagon was only one among many who could hardly believe his eyes and ears.

Particularly striking in appearance were the male carrier pigeons. The head and upper parts were a bluish-grey color with black streaks on the scapulars and wing coverts. Iridescent mauve patches emblazoned the outsides of its throat, turning to a reddish-brown at the breast, like that of a robin. Glistening splashes of faint yellow accented each clavicle like symmetrical golden brooches. The females— a muted version of their male counterparts— laid just a single egg, and the wild, monogamous bird couples flew across North America to the eastern deciduous forests where they nested in strong beeches and sturdy oaks.

Sirens of the sky

If only we had a recording of what those giant flocks sounded like, maybe those of us who are younger than 107 could begin to understand their magic. It must have been beautiful and tantalizing, if terrifying at times. They migrated in numbers sometimes as great as three billion.

A powerful evolutionary adaptation, their strength-in-numbers helped them escape predators and take advantage of acorns and beechnuts without sharing them with competitors. Yet, it was this same quality that ultimately rendered them more vulnerable to their human predators: their flock could be taken out all at once with the right weaponry. If you were a single crow, on the other hand, I doubt you would attempt to fight a ravaging mob of hungry carrier pigeons for your meal. Graceful and fast, they could fly 60 miles-per-hour and it was said they took hours, or even days, to pass over a town or valley, their great cacophony rendering a normal conversation below practically inaudible.

Not only were these gargantuan flocks both a spectacle and earful to behold—“a feathered tempest,” in the words of conservationist Aldo Leopold— they also played an important ecological role. As they plowed through forests, branches would break, allowing sunlight to permeate the darkened deritus. Their excrement fertilized great swaths of land below them, enabling plants to grow in greater abundance in the rich soil they left behind.

Not all folks celebrated their arrival. Farmers often cursed the sudden winged storms as the birds descended upon their crops, their frenzied beaks devouring everything in sight. In contrast, hunters prized them for their valuable, succulent meat; another portent of the birds' ultimate demise as a species.

Able to hear an approaching flock from miles away, men might dash for their guns as the deafening murmuration filled the sky and a blanket of dark wings cloaked the firmament below in shadow. In another of Pokagon’s recollections, he recounts how the precision of the flocks would “pour its living mass” toward the earth as the birds dropped from their course, falling “like meteors from heaven.”

Some hunters were intimidated by the powerful riot of beaks and wings. In 1871 a gathering of poachers became so overwhelmed by the sound and spectacle of them that some dropped their guns and ran. “Imagine a thousand threshing machines running under full headway,” one of them was quoted to have said in a Wisconsin newspaper, The Commonwealth. The man continued, “—accompanied by as many steamboats groaning off steam, with an equal quota of R.R. trains passing through covered bridges—imagine these massed into a single flock, and you possibly have a faint conception of the terrific roar.”

Unfortunately for the pigeons, too many gunmen remained undeterred by their powerful presence. Hence, researchers today agree that the passenger pigeon was hunted out of existence; an outcome not only born of the hunters' desire for their meat but of the fallacy that no amount of conquest could diminish so abundant a bird. In fact, both professional and amateur hunters used every way they could think of to exploit the delicious and profitable bird. According to a mournful Pokagon, the hunters would

• shoot them out of trees.

• poison them with whiskey-soaked corn.

• suffocate them with smoking sulfur.

After witnessing this, Pokagon lamented in his journal that some kind of divine punishment must be “awaiting our white neighbors who have so wantonly butchered and driven from our forests these wild pigeons." The hunters, he reported, massacred hundreds at a time by lighting a “match to the bark of the tree at the base, when with a flash—more like an explosion—the blast would reach every limb of the tree.” He then described how the young squabs would “burst open upon hitting the ground” as the men ran to safety, returning later for their spoils.

Writer Joel Greenberg collected other dramatic stories about the extinct pigeon for his book A Feathered River Across the Sky; one from residents of Columbus, Ohio in 1855. These townsfolk noticed a “low-pitched hum” coming from the horizon one morning. The sound increased to a fever pitch as “children screamed,” grown men dropped to their knees and prayed, and women “grabbed their skirts and hurried for the shelter of stores.” As spooked horses fled and a giant, sinister shadow crept over their homes, the residents feared the apocalypse had come. But the busy presence in the sky was only a harmless flock of passenger pigeons. 50 years after they had feared the end of times, life went on, but the passenger pigeon was gone forever. Or was it?

Moral questions about reverse-extinction

Thirteen ordinary-looking pigeons now live in a small coop at a research facility near Melbourne, Australia. Not unlike the birds you see clucking about on city statues and park benches, these descendants of the rock pigeon have a small but important distinction. They are the first pigeons to harbor the Cas9 gene; an essential component of the CRISPR gene-editing tool.

Each squab born to these unique 21st-century parents will contain the historic Cas9 gene in every one of its cells. Scientists can then edit its genomic makeup with DNA taken from preserved specimens of the extinct passenger pigeon. It’s a bit like the Jurassic Park series, except that the new/old species can’t eat you alive. If all goes as planned, these high-tech chicks will be the first birds to contain exact traits from a creature that no longer exists. (Do you foresee a future production of Pigeon Park where they get one of the genes wrong and the birds actually do eat you alive? Yeah, me too.)

Ben Novak, the “papa” of the flock and founder of the Revive & Restore project, hopes to “re-create” the passenger pigeon. But, should we, as humans, undertake such a feat? Critics of his work note that if we have not resolved the issues that led to the bird's extinction, won’t the re-created species simply disappear again? If this is the case, they ask, then what’s the point of re-creating it?

The making of new/old birds

None-the-less, the Revive & Restore team plans to breed the new passenger pigeon look-alikes in captivity before letting them into the wild sometime in the 2030s. Novak argues that North American forests could be a stable habitat for the new population. Furthermore, he imagines that animals like these— who are brought back from extinction—could draw the public to special zoos, generating revenues for wildlife protection. Yet, not all of his peers are so optimistic.

Beth Shapiro, a scientist who also works on sequencing the passenger pigeon genome, admits that she is apprehensive about bringing back an extinct species. She believes that a re-introduced passenger pigeon could easily face re-extinction. The vast forests that existed in North America before European settlement, she reminds us, are unrecognizable to those of today. The bird thrived in forests that supported billions of them. Since the passenger pigeon has been gone, most of those forests have been chopped down to make way for cities, highways, and farmland.

“The habitat the passenger pigeons need to survive is also extinct,” Shapiro tells Amy Marcus of the Wall Street Journal. Shapiro prefers to focus on using the passenger pigeon’s genome to help other endangered bird species survive instead of bringing the species back to life. Moreover, she stresses that a genetic copy of the bird will lack the guidance of other passenger pigeons to model their behavior after. In other words, these genetic replicas may look like the real thing, but how will they know how to behave?

Lonely Martha

Martha, the last of the passenger pigeons, died at the ripe old age of 29 in 1914 at the Cincinnati Zoo. Since then, the bird’s extinction remains a sobering reminder of what can befall a once-abundant species when no precaution is taken to protect it. Indeed, its extinction helped to motivate the birth of the conservation movement in the early 20th century. Even before Martha’s death, Republican John F Lacey of Iowa proposed the first wildlife protection measure which banned the transporting of illegally hunted game.

“The wild pigeon, formerly in flocks of millions,” he said on the House floor, “has entirely disappeared from the face of the earth.” He went on to offer a warning against nature’s “slaughter and destruction” by concluding: “Let us now give an example of wise conservation of what remains of the gifts of nature.” That same year Congress passed the Lacey Act, followed by the more robust Weeks-McLean Act in 1913 and, finally, the Migratory Bird Treaty Act soon after.

Tragically, 13 percent of birds are threatened today, according to the International Union for Conservation of Nature. That says nothing of the 25 percent of mammals and 41 percent of amphibians at risk of extinction primarily resulting from human activity. Once teeming in the trees of the Middle East, the northern bald ibis nears extinction due to over-hunting and loss of habitat. The numbers of the beloved whooping crane of North America have been whittled away to the teens because of wetland destruction. (Fortunately, though, recent protective measures have been established along their migration route and they have slowly bounced back to a few hundred.)

Countless plants and animals are disappearing right before our eyes. It's nearly unbearable for nature-lovers, a term that could describe so many of us, to face our situation head-on. But, face it, we must. For, if public apathy contributed to the extinction of the passenger pigeon—and it most certainly did— then it's only logical that it will do the same to countless other species today.

The problem can be summed up in a line in the Joni Mitchel song Big Yellow Taxi: “You don’t know what you’ve got til’ it’s gone.” Perhaps we can begin to know the enormity of the loss in retrospect. Yet, back when passenger pigeons were abundant, very few people thought humanity could have any major impact on their population. Even the famous 19th-century naturalist John James Audubon dismissed the idea.

Echoes of this kind of denial reverberate today in the context of responses to climate change. Even though Nasa reports that 97 percent or more scientists agree that the earth is rapidly warming due to human activity, many people choose to look the other way. How could we humble humans have such a great impact on global climate, they ask?

Greenberg compares the unmistakable similarities of the nineteenth-century political rhetoric about the bird industry to statements about climate change today: “The industry that paid people to kill these birds said, ‘If you restrict the killing, people will lose their jobs,’ ” he writes of the arguments against early 20th-century conservation—“the very same things you hear today” from politicians about climate change.

Ultimately, we do have choices, of course. We could bring back some of our extinct species, like Novak’s genetically manipulated pigeons. Yet, would it be ethical to send them right back into a hostile, man-made environment, thick with exhaust to choke them, petroleum to muddle their feathers, and breeding grounds few and far between? Or instead, we could focus on protecting the species we have now, dedicating all of our resources to them. Perhaps we could do a little of both and then shake up the Magic 8 Ball. But where do we draw the line? Will we bring back neanderthals next?

Most importantly, have we learned our lesson?

I see it a bit like choosing to get a pet. If you live in the city and are gone all day, maybe it’s best to pass on that puppy whose picture you've fallen in love with on the internet. In contrast, if you live on a farm, if you play with baby goats and milk the cows in the sunshine all day, maybe a puppy would thrive. He likely wouldn’t thrive in a small apartment alone all day with a walk or two around the block with a paid stranger.

Might this be the fate of the passenger pigeon if we bring him back in the 21st-century? Will he be trapped in cities and longing for trees? I can see him now, searching endlessly for his giant flock to show him how it's done, surrounded by strip malls and Starbucks overflowing with human predators carrying guns. That feels like a sad fate for such a noble bird. I say: we must learn to protect them first before we bring them back. But let's get to work because I want to live in a world where the trees are—in the words of Aldo Leopold in his 1947 Monument to the Pigeon—"shaken by a living wind."