The passenger pigeon (Ectopistes migratorius ), perhaps the world's most abundant bird species at one time, became extinct due directly to human activity. In the mid-1800s passenger pigeons travelled in flocks of astounding numbers. Alexander Wilson, the father of American ornithology, noted a flock he estimated to contain two billion birds. The artist and naturalist John James Audubon once observed a flock over a three-day period and estimated the birds were flying overhead at a rate of 300 million per hour.
The species became extinct within a span of 50 years, several factors having led to its rapid demise. The passenger pigeon was considered an agricultural pest , thus providing ample reason to kill large numbers of the birds. It was also in demand as food, largely due to the fact that nesting flocks were easily accessible. Young squabs were easy prey for hunters who knocked them from their nests or forced them out by setting fires below them. Adults were also killed in huge numbers. They were baited with alcohol-soaked grain or with captive pigeons set up as decoys, then trapped and shot. A common practice of the day was to use the live pigeons as targets in shooting galleries. In 1878, near Petoskey, Michigan, a professional market hunter earned $60,000 by killing over three million passenger pigeons near their nesting grounds. Once killed, many of the birds were packed in barrels and shipped to cities where they were sold in markets and restaurants. The demand was particularly high on the East Coast where forest clearing and hunting had already eradicated the species from the area.
By the 1880s commercial hunting of passenger pigeons was no longer profitable, because the population had been depleted to only several thousand birds. Michigan provided their last stronghold, but that population became extinct in 1889. The remaining small flocks of birds were so spread out and isolated that their numbers were too low to be maintained. The disruption of the population in the 1860s and 1870s had been so severe that breeding success was permanently reduced. At one time the sheer numbers of passenger pigeons in a flock was enough to discourage potential predators. Once the population was split into small, isolated remnants, however, natural predation also contributed to the species' rapid decline.
The last individual passenger pigeon was a female named Martha, which died in the Cincinnati Zoo in 1914. It is now on display at the National Museum of Natural History in Washington, D.C.
[Eugene C. Beckham ]
Schorger, A. W. Passenger Pigeon: Its Natural History and Extinction. Norman, OK: University of Oklahoma Press, 1973.
Wilcove, D. "In Memory of Martha and Her Kind." Audubon 91 (September 1989): 52–55.
Worsnop, R. L. "Evolving Attitudes." CQ Researcher 2 (January 24, 1992): 58–60.