The Passenger PigeonEctopistes migratorius, is an extinct North American bird. The species lived in enormous migratory flocks until the early 20th century, when hunting and habitat destruction led to its demise. One flock in 1866 in southern Ontario was described as being 1 mi wide and 300 mi long, took 14 hours to pass, and held in excess of 3.5 billion birds. That number, if accurate, would likely represent a large fraction of the entire population at the time.
Some estimate 3 to 5 billion Passenger Pigeons were in the United States when Europeans arrived in North America. Others argue the species had not been common in the pre-Columbian period, but their numbers grew when devastation of the American Indian population by European diseases led to reduced competition for food.
The species went from being one of the most abundant birds in the world during the 19th century to extinction early in the 20th century. At the time, Passenger Pigeons had one of the largest groups or flocks of any animal, second only to the Rocky Mountain locust.
Some reduction in numbers occurred from habitat loss when European settlement led to mass deforestation. Next, pigeon meat was commercialized as a cheap food for slaves and the poor in the 19th century, resulting in hunting on a massive and mechanized scale. A slow decline between about 1800 and 1870 was followed by a catastrophic decline between 1870 and 1890. Martha, thought to be the world's last Passenger Pigeon, died on September 1, 1914, at the Cincinnati Zoo.
The Passenger Pigeon was a member of the pigeon and dove family Columbidae and was originally described in 1766 as Columba migratoria by Carl Linnaeus. In 1827 William John Swainson moved the Passenger Pigeon from the genus Columba to the newly erected monotypic genus Ectopistes due in part to the greater length of the tail and wings, larger size, sexual dimorphism, and lack of a facial stripe.
The Passenger Pigeon's closest living relatives were originally thought to be the Zenaida doves, particularly the Mourning Dove, based on morphological grounds. The Mourning Dove was even suggested to belong to the genus Ectopistes and was listed by some authors as E. carolinensis. However, genetic analysis in 2010 demonstrated that the Passenger Pigeon was in fact closely related to the American Patagioenas pigeons, including western North America's Band-tailed Pigeon, to which the Passenger Pigeon may have been an eastern counterpart. Ectopistes and Patagioenas were shown to belong to a different clade of pigeons than the Zenaida doves, and were most closely related to the Southeast Asian cuckoo-doves in the genera Macropygia and Reinwardtoena.
More than 130 Passenger Pigeon fossils have been found scattered across 25 states and provinces. These records date as far back as 100,000 years ago in the Pleistocene era, during which the pigeon's range extended at least to California and other Western states that were not a part of its modern range.
The common name "Passenger Pigeon" derives from the French word passager, which means "to pass by" in a fleeting manner. The generic epithet translates as "wandering about", the specific indicates it is migratory; the Passenger Pigeon's movements were not only seasonal, as with other birds, but they would also mass in whatever location was most productive and suitable for breeding. While the pigeon was extant, the name Passenger Pigeon was interchangeable with Wild Pigeon. It also gained a number of less-frequently used names, including Blue Pigeon, Merne Rouck Pigeon, Wandering Long-tailed Dove, and Wood Pigeon.
The Passenger Pigeon was much larger than the somewhat similarly-plumaged Mourning Dove. Physically it was adapted for speed and maneuverability in flight, with a small head and neck, long and wedge-shaped tail, and long, broad, and pointed wings. It had particularly large breast muscles that enabled it to fly for long distances.
The adult male Passenger Pigeon had a blueish-gray head, nape, and hindneck. On the sides of the neck and the upper mantle were display feathers that had a bright violet to golden-green iridescence. The upper back and wings were a pale gray that turned into grayish-brown on the lower wings. The bird's secondaries and primaries were a blackish-brown with a narrow white edge on the outer side of the feather.
While many observers described the noise produced by flocks of Passenger Pigeons as deafening, the only scientific notes on the species' calls come from a small captive flock. Generally, the bird's voice was loud, harsh, and unmusical. One call was a simple harsh "keck" that could be given twice in succession with a pause in between.
The Passenger Pigeon was found across most of North America east of the Rocky Mountains. The Passenger Pigeon was one of the most social land birds. It lived in colonies stretching over hundreds of square miles and practiced communal breeding with up to a hundred nests in a single tree. At the height of its population of three to five billion it may have been the most numerous bird on Earth, and A. W. Schorger believed that it accounted for between 25 and 40% of the total landbird population in the United States. Even today the Passenger Pigeon's historic population is roughly the equivalent of the number of birds that overwinter in the United States every year.
The Passenger Pigeon was nomadic and had no site fidelity, often choosing to nest in a different location each year. Pigeon migration, in flocks numbering billions, was a spectacle without parallel. John James Audubon described one flock he encountered with the words:
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 traveled 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... Before sunset I reached Louisville, distance from Hardensburgh fifty-five miles. The Pigeons were still passing in undiminished numbers, and continued to do so for three days in succession. Others frequently described these flocks as being so dense that they blackened the sky and as having no sign of subdivisions. These migrating flocks were typically in narrow columns that twisted and undulated, but they were reported as being in nearly every conceivable shape.
The specimen shown here is a stuffed Passenger Pigeon at the Nature Center of Point Pele National Park, Ontario, Canada.