In the autumn of 1813, naturalist John James Audubon was journeying through the barrens of Kentucky when he heard a rumble from an approaching front on the northeast horizon. Within minutes, the sky had darkened, the temperature had plummeted and the thunderous roar had become deafening. This was no gale blowing in, however, but a massive storm of passenger pigeons so thick that the birds blotted out the sun, created a chilly downdraft from their flapping wings and snapped limbs clean off trees when they roosted en masse.
“The air was literally filled with Pigeons; the light of noon-day was obscured as by an eclipse; the dung fell in spots, not unlike melting flakes of snow,” Audubon wrote. Spellbound by “the extreme beauty of their aerial evolutions” that undulated like “the coils of a gigantic serpent,” Audubon attempted to get a count of the flock, but the numbers were staggering. The avian cloud took three days to pass overhead.
The massive flocks of passenger pigeons reported by 19th-century observers like Audubon were of biblical proportions. By some estimates, as many as five billion passenger pigeons, also known as wild pigeons, filled the skies of eastern North America and accounted for a quarter of the continent’s birds in the early 1800s. Yet by the end of the century, what naturalist John Muir once likened to “a mighty river in the sky” had run dry.
Passenger pigeons—not to be confused with “carrier pigeons” used to transport messages—had vanished from the wild by 1900, and within a few years the planetary population had dwindled to a mere two held in captivity at the Cincinnati Zoo, a couple with the patriotic names of George and Martha in honor of the Washingtons. When George died in 1910, Martha was the sole survivor. Since she had never laid a fertile egg and the zoo’s $1,000 reward for any male passenger pigeon to mate with her had remained unclaimed, extinction was a foregone conclusion. The end came on September 1, 1914, when keepers came to Martha’s cage and found no life in her deep-red eyes. At the precise moment when the last passenger pigeon died from an apoplectic stroke, a species vanished from the earth.
How had this happened? No detailed autopsy was required to determine the cause of death for the passenger pigeon species. Rampant overhunting and the destruction of natural habitats were to blame. Passenger pigeons, which more closely resembled mourning doves than the common pigeons found today, made for tasty and cheap meals and their iridescent red, blue and copper plumage and long tails made for fashionable accents to women’s hats. The tendency to flock together made these birds of a feather easy prey as the commercial passenger pigeon industry blossomed. Even the worst marksman could simply point a gun airborne, fire and bag hundreds of birds. Hunters also captured them by the thousands with nets and choked them by the dozens by placing burning sulfur under their nests. But even as hunters harvested millions of birds annually in the first half of the 1800s, the passenger pigeon population remained steady.
Technology, however, caught up to the fast-flying birds in the second half of the 1800s. Bands of hunters shared news of approaching flocks over newly laid telegraph wires, while railroads allowed large numbers of harvested pigeons to be transported to America’s burgeoning cities and sold for food. In addition to the mass slaughter, when Americans cut down virgin forests as the country swept westward, they depleted the passenger pigeons’ food supply of beechnuts, acorns, chestnuts, seeds and berries. The species could not replenish faster than it was being diminished. Females usually laid only one egg at a time in their nests, and passenger pigeons required large numbers of their own kind in proximity in order to breed. When their numbers dwindled, their reproductive cycles shut down.
By the time the public realized there was a problem, it was already too late. “The wild pigeon, formerly in flocks of millions, has entirely disappeared from the face of the earth,” Iowa Republican Congressman John F. Lacey lamented to Congress in 1900 as he introduced the country’s first wildlife protection bill, which banned the interstate sale of poached game. “We have given an awful exhibition of slaughter and destruction, which may serve as a warning to all mankind.”
Ultimately, the passenger pigeon could not be preserved, but Martha could. After she was found dead in her cage, the Cincinnati Zoo as planned shipped the body with a 300-pound block of ice to the Smithsonian Institution for preservation and mounting for display in its bird collection. After being out of view for years, Martha has been retouched and perched on a branch for a new exhibition at the Smithsonian’s National Museum of Natural History. Other museums, conservation groups and natural history centers are marking the centennial of the passenger pigeon’s extinction with special programs and exhibits, and they hope the story will be a cautionary tale. Some scientists are seeking to bring the species back to life and eventually reintroduce it into the wild through a high-tech process known as “de-extinction,” but as of now the passenger pigeon remains grounded.