passenger pigeon

Joel Greenberg / Project Passenger Pigeon

Passenger pigeons once outnumbered all other birds in North America. When migrated they moved in huge flocks, sometimes comprising more than a billion birds. The largest nesting ever recorded covered 850 square miles.

That was in 1871. Just a few decades later, passenger pigeons were all but gone from the wild.

By the end of 1914 they were extinct.