"The passenger pigeon, from the Columbidae family, is believed to be extinct in the wild since around the 1900's, and completely extinct since 1914, when the last remaining passenger pigeon died at the Cincinnati Zoo. The main reason for their extinction was overhunting, however, there were many other factors to blame, such as deforestation. It began with the Native Americans hunting them, but was intensified following the arrival of the Europeans, and intensified once more when it was commercialized as cheap meat. This lead to mass hunting, following a slow decline beginning at around the 1800s, then gaining speed at around the 1870's, ending with what is believed to be last wild passenger pigeon being shot in 1900."

I really like this paragraph by John James Audubon, I'll put it in the next message below.

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.