The tale of the passenger pigeon is one of the most tragic extinction stories of modern times. It was actually the most common bird in North America as recently as 200 years ago, and some reports counted single flocks numbering in the billions. So what happened?
The pigeon meat was commercialized and sold as cheap food, mostly for slaves and the poor, which began an unregulated hunting campaign on a massive scale. In 1896, the final flock of 250,000 were killed by a group of hunters who actually knew that it was the last flock of that size in existence. Not a single bird was left behind.