This wild North American pigeon was named not for its ability to transport passengers, but for its wanderlust tendency to pass by (passager, in the French), before gradually passing out of existence for good, due to hunting and widespread deforestation in the nineteenth century. Living in the deciduous groves of eastern North America and breeding around the Great Lakes, the passenger pigeon's population at one point numbered between three and five billion. (A similar number range occurs in the dating of its oldest known fossil: from a specimen found in North Carolina estimated to be between 3.6 to 5.3 million years old.) It could reach airborne speeds of sixty-two miles (one hundred kilometers) per hour and caught light in its iridescent neck feathers. Wallace Craig attempted to record a different kind of tonal richness: the male pigeon's vibrant vocalizations, in musical notation and phonetic imitation, as it moved gently toward its mate: "kee-kee-kee-kee", "tete! tete! tete!" This chattering call sounded from one of the most social land birds, whose scale of loss is almost inconceivable: at their peak, passenger pigeon populations were about equal in number to all the birds that currently overwinter in North America. To give a sense of this figure, Christopher Cokinos believes that if all of the pigeons flew in a single line, they would have ringed Earth twenty-two times. For fifteen thousand years, before the arrival of European colonizers, Native American land-use practices, it is thought, worked in symbiotic relation with the birds --- promoting tree species that produced nuts, acorns, and fruits upon which the pigeons fed. Maritime explorer Jacques Cartier was the first European to record the passenger pigeon in 1534. Soon after, René Laudonnière, the French Huguenot founder of Fort Caroline, reported killing almost ten thousand pigeons over the course of a few weeks. The advent of railroads and telegraphs facilitated the tracking of flocks as hunting continued to accelerate, due, in part, to the eighteenth and nineteenth century belief that the pigeon had medicinal properties. Its decline was noted by Bénedict Henry Révoil in 1856, who foresaw the pigeon's fate. "Everything leads to the belief that the pigeons, which cannot endure isolation and are forced to flee or to change their way of living according to the rate at which North America is populated by the European inflow, will simply end by disappearing from this continent", he wrote. "[I]f the world does not end this before a century, I will wager. . . that the amateur of ornithology will find no more pigeons, except those in the Museums of Natural History." How right he was. The last recorded wild sighting was around 1900, and the final captive passenger pigeon, named Martha, died in 1914 at the Cincinnati Zoo. The pigeons were remembered by naturalist Aldo Leopold, who wrote these moving words at the close of World War II: "Men still live who, in their youth, remember pigeons. Trees still live who, in their youth, were shaken by a living wind. But a decade hence only the oldest oaks will remember, and at long last only the hills will know." Martha's likeness was painted by muralist John A. Ruthven in 2014.