For thousands of years they filled the skies. On September 1, 1914 they disappeared forever.

From Billions to None: The Passenger Pigeon's Flight to Extinction

The passenger pigeon, the most abundant bird species in North America for thousands of years, became extinct by human hands in a geologic heartbeat. Its story remains relevant to conservation challenges today, and there are even plans for its possible revival. Rare archival material, CGI animation, and aerial cinematography combine to recreate the awe-inspiring nature of these birds.

Directed by David Mrazek