The real onslaught began with the onset of large-scale commercial hunting carried out by well-organised trappers and shippers in order to supply the developing cities on the east coast of the United States with a cheap source of meat. It began once railways linking the Great Lakes area with New York opened in the early 1850s. By 1855 300,000 pigeons a year were being sent to New York alone. The worst of the mass slaughter took place in the 1800s and 1870s. The scale of the operation can be judged by figures that seem almost incredible but which were carefully recorded as part of a perfectly legal and highly profitable commerce. On just one day in 1860 (23 July) 235,200 birds were sent east from Grand Rapids in Michigan.
Not surprisingly, even the vast flocks of pigeons could not withstand slaughter on this scale. Numbers fell rapidly and by the late 1880s large flocks, which had once been so common, had become a matter for comment and investigation, and most were no more than a few hundred strong. The last known specimens were seen in most states of the eastern United States, in the 1890s, and the passenger pigeon died out in the wild in Ohio about 1900. The last survivor of a species that had once numbered 5 billion died in captivity in 1914.
–Clive Ponting, A Green History of the World
