|Population||est. 4-10 billion in 1820|
The passenger pigeon (Ectopistes migratorius) was a species of bird, of the order Columbiformes, which once existed in the eastern part of North America. Among the most numerous animals in history, its spectacular extinction at the hands of man raised awareness for wildlife conservation, and better protections for threatened species.
It was referred to as "wild pigeon", "wood pigeon", or "red-breasted pigeon" by colonial Americans. The name "passenger pigeon" comes from the term "bird of passage", referring to its migratory habits; indeed, its scientific name, Ectopistes migratorius, carries the implication of "wandering," and flocks of passenger pigeons had a habit of moving from one location to another within a season in addition to normal migration, selecting the most favorable sites for feeding and nesting.
The passenger pigeon male was about 16.5 inches long, with a small head and neck, pointed bill, and long, pointed wings powered by large breast muscles capable of sustaining the bird on long flights. The tail feathers were long and wedge-shaped. The females were slightly smaller.
The head and upper section of males was a bluish-gray; the throat and breast were rose, which faded to white further down. The sides of the throat bore small patches of iridescent pink, which changed color to a shimmering green, purple and bronze. Females were of similar coloration, but duller over-all.
The mourning dove, Zenaidura macroura, has been confused with the passenger pigeon, but it is a smaller bird which makes a whistling sound with its wings while in flight; the passenger pigeon was silent.
Acorns, chestnuts, and beechnuts made up the bulk of their diet, supplemented by smaller seeds, berries, and insects and worms that they found within the forests; when the supply was depleted they took to the wing in search of new areas to feed. Naturalist John Muir described a feeding technique when "...a comparatively small flock swept thousands of acres perfectly clean of acorns in a few minutes, by moving straight ahead with a broad front. All got their share, for the rear constantly became the van by flying over the flock and alighting in front, the entire flock constantly changing from rear to front, revolving something like a wheel with a low buzzing wing roar that could be heard a long way off."
The birds nested in forests, with fifty or more nests per tree, laying one or two white eggs in a structure loosely-made from twigs. Both parents cared for the egg and hatched chicks, but after two weeks the chicks would be abandoned when the flock left the area, dropping to the ground to fend for themselves until they were able to fly a few days later (Fuller 1987). Speculation exists as to whether or not there were two nestings per season, but this is not proven, and early naturalists did not leave a report on the subject. 
The range of the passenger pigeon included the large hardwood forested areas of eastern North America, breeding as far north as Maine, Quebec, and northern Ontario, and as far south as northern Mississippi westward to Kansas. Southern migrations took it to the Gulf coast between Florida and Texas, with stragglers seen as far south as Guatemala, or as far west as Oregon.
The passenger pigeon was first described by Europeans in July, 1605, when Jesuit priest Samuel de Champlain saw "infinite number of pigeons" on islands off the coast of Maine, of which he took a great quantity; many early historians also mention the birds. John Lawson, in his A New Voyage to Carolina (1709), speaks of prodigious flocks of pigeons at the beginning of the 18th century, in which "they sometimes split off the Limbs of stout Oaks, and other Trees, upon which they roost o' Nights." The early settlers in Virginia found the pigeons in winter "beyond number or imagination."
Even then, people were seeing massive flocks of birds that filled the skies, sometimes for days. Three of the most famous naturalists in American history were the first to realize the passenger pigeon numbered in the billions. The founder of North American ornithology was Alexander Wilson, and in 1806 he was amazed by the sheer number of birds:
- "But the most remarkable characteristic of these birds is their associating together, both in their migrations, and also during the period of incubation, in such prodigious numbers as almost to surpass belief, and which has no parallel among any other of the feathered tribes on the face of the earth with which naturalists are acquainted. These migrations appear to be undertaken rather in quest of food, than merely to avoid the cold of the climate, since we find them lingering in the northern regions, around Hudson's Bay, so late as December; and since their appearance is so casual and irregular, sometimes not visiting certain districts for several years in any considerable numbers, while at other times they are innumerable." 
Another was John James Audubon, who would go on the fame creating the great "elephant folio" of North American birds, wrote:
- "In the autumn of 1813, I left my house at Henderson, on the banks of the Ohio, on my way to Louisville. In passing over the Barrens a few miles beyond Hardensburgh, I observed the Pigeons flying from north-east to south-west, in greater numbers than I thought I had ever seen them before, and feeling an inclination to count the flocks that might pass within the reach of my eye in one hour, I dismounted, seated myself on an eminence, and began to mark with my pencil, making a dot for every flock that passed. In a short time finding the task which I had undertaken impracticable, as the birds poured in in countless multitudes, I rose, and counting the dots then put down, found that 163 had been made in twenty-one minutes. I travelled on, and still met more the farther I proceeded. 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; and the continued buzz of wings had a tendency to lull my senses to repose."
The naturalist John Muir also saw pigeons in huge numbers, and during one hunt witnessed the arrival of a flock:
- "Every thing was ready, and all eyes were gazing on the clear sky, which appeared in glimpses amidst the tall trees. Suddenly there burst forth a general cry of "Here they come!" The noise which they made, though yet distant, reminded me of a hard gale at sea, passing through the rigging of a close-reefed vessel. As the birds arrived and passed over me, I felt a current of air that surprised me. Thousands were soon knocked down by the pole-men. The birds continued to pour in. The fires were lighted, and a magnificent, as well as wonderful and almost terrifying, sight presented itself. The Pigeons, arriving by thousands, alighted everywhere, one above another, until solid masses were formed on the branches all round. Here and there the perches gave way under the weight with a crash, and, falling to the ground, destroyed hundreds of the birds beneath, forcing down the dense groups with which every stick was loaded. It was a scene of uproar and confusion. I found it quite useless to speak, or even to shout to those persons who were nearest to me. Even the reports of the guns were seldom heard, and I was made aware of the firing only by seeing the shooters reloading."
Muir also witnessed large-scale hunting of these birds. The young United States was moving west on the tracks of the new railroad, settling in newly-created towns and cities, and to feed them all required a lot of food, much of which was readily available in pigeons. Hunters went into the woods, already thick with pigeons; they used shotguns, lit fires underneath the trees, or simply knocked them out of the branches with long poles. In cities like New York, squab was selling at a rate of 18,000 a day. So many were killed that Audubon wrote "The pigeons were picked up and piled in heaps, until each [hunter] had as many as he could possibly dispose of, when the hogs were let loose to feed on the remainder". By 1850 a decline in the number of flocks was noticed. With the hunting came the loss of habitat; hardwood forests on the east coast were felled in so many large areas that, concurrent with the hunting, the passenger pigeon was considered extinct east of the Appalachian Mountains.
In 1878, the last great hunt occurred near Petoskey, Michigan, in which over three million birds were taken at a rate of 50,000 per day. The later hunts were fewer, but better-coordinated; hunters would have the advantage of the telegraph and a dedicated watch for flocks.
In the late 1890's, state lawmakers passed laws calling for a ten-year moratorium on pigeon hunting; some passed laws calling for penalties against hunters. By then it was too late. In addition to over-hunting and the loss of woodland habitat, the pigeons fell victim to their own breeding habits: they could not successfully breed unless they were in large flocks. Rewards were offered for the collection of live pigeons to supplement the few in captivity; however, there was still some price on the heads of those needed for food. The last confirmed passenger pigeons in the wild were shot at Babcock, Wisconsin in 1899, and in Pike County, Ohio on March 24, 1900.
This left three in captivity, all in Cincinnati, two males, and a female named Martha. She out-lived the others by a number of years before dying at 1:00 pm on September 1, 1914, the only extinction of a species that has been documented to the time and date. A $1,000 reward offered by the zoo for a mate went unclaimed.
- Audubon, John James. Birds of America (1831); digitized copy at the University of Pittsburgh
- Fuller, E. Extinct Birds; Facts On File Publications, New York, 1987.
- Schorger, A. W. The Passenger Pigeon; University of Wisconsin Press, Madison, Wisconsin, 1955.
- Weidensaul, S. The Birder’s Miscellany; Simon & Schuster, New York, 1991.