One morning in 1855, residents of Columbus, Ohio, noticed a “low-pitched hum” in the distance, and clouds gathering on the horizon. The sound increased, according to a later telling, “to a mighty throbbing. Now everyone was out of the houses and stores, looking apprehensively at the growing cloud, which was blotting out the rays of the sun. Children screamed and ran for home. Women gathered their long skirts and hurried for the shelter of stores. Horses bolted. A few people mumbled frightened words about the approach of the millennium, and several dropped on their knees and prayed.”

This story is collected in Joel Greenberg’s new book, A Feathered River Across the Sky, and describes an event not apocalyptic or even meteorological but instead avian. The cloud over Columbus consisted of passenger pigeons, whose numbers in North America were once incomprehensibly large: three to five billion, according to Greenberg, when Europeans arrived on the continent. One witness in Ontario saw a single flight later calculated to comprise more than a billion birds—perhaps three times as many. Descriptions of flocks overhead recall old stories of bison thundering in herds down hillsides, and in fact the pigeon met the fate that the buffalo escaped: about 50 years after these accounts, it was extinct. The last of the species, named Martha, died at the Cincinnati Zoo in 1914.

A researcher at the Field Museum and the Peggy Notebaert Nature Museum, Greenberg writes a fascinating sort of biography of the bird, detailing its habits, its interactions with other species—most inauspiciously humans—and its eventual demise. The pigeon’s disappearance was so sudden as to be confusing; Henry Ford believed the whole species may have drowned in the Pacific Ocean as it tried to fly abroad. “What is indisputable is that their population was bewilderingly vast in 1860 but virtually gone by 1900,” Greenberg writes.

The simpler explanation is that the pigeons were hunted until they vanished. They were shot for food and sport and seemed, because of their numbers and their dense nesting patterns, to be easy pickings: one of the last great hauls, in 1870, brought in five or six tons of pigeons every day for a two- or three-week period. At times, prices were so low that a dozen pigeons could be traded for a loaf of bread. The new North Americans were aided by their innovations: advancing communications technologies made it easier to spread word of a large pigeon roost, and train travel made it easier to get there. The largest nesting of all, covering 850 square miles of Wisconsin, drew 100,000 visitors in 1871.

Greenberg writes the pigeon’s history in so linear a fashion that he hardly pauses to offer an introduction, though an outline of his intentions wouldn’t have hurt this project. (There’s a very short preface.) Feathered River is characterized by its urgency, and by Greenberg’s passion: he uses words like “slaughter” and “carnage” so often that there’s little doubt where his sympathies lie. His tone is mournful; at the end of a chapter on the role of the pigeon in Native cultures, he writes, “The link between a people and a bird started before recorded time and would only conclude with the decimation of the latter. Living for one became more difficult; living for the other impossible.”

The first European description of the passenger pigeon comes from Jacques Cartier, who observed it on Prince Edward Island in 1534. Cartier was not the first European on record to have killed a passenger pigeon, though; Greenberg adds, “Perhaps he and his crew were sated by the casks of great auks they had collected and salted earlier”—the auk being another bird not long for the developing world. A fearsome researcher, Greenberg excels in this sort of side detail, with an exhaustiveness that is at times exhausting. It’s most powerful toward the end of the book, when we watch the species dwindle, sometimes bird by bird. He tallies today’s threatened species and reminds us that scientists believe the world to be in its sixth great period of mass extinction—due to human intervention.

Plenty of other stories are lively and weird, and reflect what an iconic species the passenger pigeon was: for instance one about Junius Booth (father of John Wilkes), who asked the Unitarian minister James Freeman Clarke to help him find a grave site “for a recently departed friend”—who turned out to be a bushel of passenger pigeons over which Booth was mourning.

Clarke’s response reminded me of another recent book, Jon Mooallem’s wonderful Wild Ones, about contemporary attempts to save three endangered species: polar bears, Lange’s metalmark butterflies, and whooping cranes. (In the course of his travels Mooallem also stumbles across poor Martha, the last passenger pigeon, in a cabinet at the Smithsonian.) In the end he’s encountered enough dejected conservationists to wonder whether their task isn’t a bit Sisyphean—”just as all conservation may be, since implicit in that work now is the impossibility of its ever being finished.” But it seems the alternative is worse. “It was an error in a good direction,” Clarke reflected on Booth’s misguided compassion. “If an insanity, it was better than the cold, heartless sanity of most men.”