Peering into the garden the other day, I saw a large, mixed flock of robins and grackles. The grackles landed on the lawn and made their way across it, methodically, like grazing sheep. The robins seemed to fly lazily and aimlessly between trees, though dozens landed and many came down to my icy fish pond to drink.
An hour after this early morning frenzy, the garden was deserted. The abrupt emptiness after so much activity called to mind the improbable but total destruction of another gregarious bird, the passenger pigeon. This year marks the centenary of its extinction, when the last known individual, a caged female named Martha, fell off her perch at the Cincinnati Zoo.
This happened on Sept. 1, 1914, about a month after the great powers in Europe decided it was time to try to annihilate another creature, male humans in their prime.
World War I engulfed the planet; the plight of the passenger pigeon seemed of little consequence by comparison. In North America, the ranks of those who knew this noble but persecuted pigeon firsthand faded away as well.
In its form, the pigeon was reminiscent of the mourning dove, but quite a bit bigger and more dazzling in its plumage: The striking male was blue and gray, but like the dove and the common city pigeon had moments of opal-like iridescence. “A throat and breast of rich copper glazed with purple,” writes Joel Greenberg, an author who has chronicled this beautiful bird’s sad decline in a new book, “A Feathered River Across the Sky.”
The title refers to the spectacle witnessed by those privileged to have seen its great flocks, which were almost beyond imagination.
In 1860, a naturalist recorded a flock in Ontario that was a mile wide passing uninterrupted for 14 hours. The largest recorded nesting site covered 850 square miles — in Wisconsin in 1871. Such numbers belied the fragility of this creature. The advent of the first Internet — the telegraph — alerted hunters and cullers to the mass of birds while the railroads permitted the shipping of pigeons to market. In an age of ecological ignorance, no real conservation laws and a lamentable bloodlust for this poor animal, we blew it.
“Unrelenting carnage reduced the population to the point where it began its inexorable spiral to obliteration,” writes Greenberg. As vast as the Wisconsin nesting was, the great majority of the passenger pigeon population had been wiped out in the preceding decade.
The last wild flocks were encountered in the 1880s, Greenberg writes. The paucity of the bird by then seemed to induce an even greater urge to kill it, either as a vanishing delicacy or to mount for posterity.
The passenger pigeon was designed for rapid flight, and in its great masses it had an ability to fly fast in tight flocks. With incredible vision, reflexes and agility, it somehow avoided mid-air collisions while flying at 60 mph.
You can get a sense of this avian acumen today with other species that flock in great numbers, even if their clouds are but a shadow of the passenger pigeon’s.
The starling is a classic example. Its flocks seem to become living organisms in themselves as they bend and contort in the winter sky, often as a defense against a preying hawk.
Certain shorebirds, including sandpipers, fly rapidly at low altitude, in mass and in perfect synchronization.
We have become much better at understanding our effects on other species, but no ecosystem seems entirely safe with us around.
Greenberg writes that we still permit 19th-century-style “profligate slaughter” in the oceans, where factory farming goes on with little state intervention: “Catches of the five most coveted species of tuna, for example, have increased from a million tons a year in the mid-1960s to over 4 million currently.”
As for birds, you can look at the endangered species list to understand that some are still in peril, including certain cranes and woodpeckers.
We can help protect all our birds in practical ways: Don’t let your cat wander unsupervised. Take part in an upcoming citizen science event called the Great Backyard Bird Count. Its organizers want participants to record birds in their gardens between Feb. 14 and Feb. 17 — spend at least 15 minutes tallying the number and species of birds in your location. Participants have to sign up online beforehand in order to submit their checklists.
The international count last year drew 121,000 participants in the United States. “We find it a very useful way to track birds,” said Agatha Szczepaniak, an Audubon spokeswoman. The top 10 by checklist included common backyard birds: cardinals, house finches, chickadees, mourning doves and crows. The most numerous birds were found flocked in Missouri, 5 million redwing blackbirds and 1.5 million robins.
In recent years, Szczepaniak said, the counts have demonstrated the resurgence of the American crow, a species decimated by the West Nile Virus, which is spread by mosquitoes.
“We were able to realize that the American crow was able to rebound. It’s still in the top 10 birds in the United States,” she said.