From Billions to None: The Passenger Pigeon's Flight to Extinction (2014)
剧情：
From Billions to None follows naturalist and author Joel Greenberg and his friends on a quest to reveal the incredible, mostly forgotten story of how the passenger pigeon, the most abundant bird species in North America for thousands of years, became extinct by human hands in a geologic heartbeat. From Billions to None retells the remarkable story of the passenger pigeon and explores its striking relevance to conservation challenges today, and plans for its possible revival. Interweaving rare archival material, CGI animation that brings the flocks of millions to life and aerial cinematography, the film recreates the awe-inspiring nature of these birds, and presents passionate scientists, teachers and young people who reveal why, 100 years later, it's important to remember the event - and act.
