The demise of the passenger pigeon is a monumental tragedy and a testament to the destructiveness and stupidity of humans. Ectopistes migratorius was once the most abundant bird in the world, or at least in North America. Their migrations were described by writers of the time as truly awesome, with millions of birds taking hours to pass over a single spot, and drowning out all other sounds with the noise of an army of horses or a powerful thunderstorm. In the 1870's, their nesting sites covered thousands of square miles across the northeast and midwest of the US and Canada. But by the mid 1890's, flocks numbered once in the billions were now only dozens, in 1914 the last passenger pigeon was dead. Named Martha, she lived at the Cincinnati Zoo, and never laid a single fertile egg in her 29 years.
Ranging in huge flocks across the landscape in search of acorns and other tree-nuts, they struck fear in hearts of people and animals alike with their noise and sky-darkening masses. They often snapped off huge branches and entire tree tops from the weight of so many birds, and hunters could take many at once with a single shot, or even by just waving a pole around in the air as they passed by overhead. It was hunting that proved to be their demise, as the birds were valued for their meat. Once railways and telegraphs had been put in place, it became too easy for hunters and trappers to learn of new nesting sites and travel to them quickly. The pigeons were shot, trapped with nets, burned out of trees, poisoned with corn soaked in whiskey and asphyxiated with burning sulfur.
The huge flocks they traveled in to overwhelm predators just made them more vulnerable to humans. Ultimately, they couldn't reproduce fast enough to replace their numbers, as nesting sites were constantly being found and laid to waste. Despite the imprecations of Native Americans and a few lone conservationists of the time, there was no effort to save them. Aldo Leopold wrote the following in "On a Monument to the Pigeon" in 1947:
“Men still live who, in their youth, remember pigeons; trees still live who, in their youth, were shaken by a living wind. But a few decades hence only the oldest oaks will remember, and at long last only the hills will know.”