Project Passenger Pigeon. Website visitors can explore the animals’ taxonomic relationships, ecological needs, and the surprising role of transportation technology in their extermination. Testimonials from novelists, filmmakers, poets, and scientists reveal how a defunct creature can continue to inspire creativity and stimulate research. Perhaps most satisfying, the site provides resources and tools that help everyone get involved in telling the birds’ story, from downloadable PowerPoint presentations and exhibit posters to available speakers, children’s activity suggestions, and an origami tutorial so groups can fold their own paper flocks. And please consider contributing to all these efforts by donating to the project in general or the forthcoming film, ”From Billions to None.” once-there-were-billions>Smithsonian exhibit (“Once There Were Billions” at the Natural History Museum), and articles in Audubon,Living Bird,and the Guardian, to name a few. Many of the pieces at least mention efforts to revive the species through genetic engineering, as discussed in a TED talk by researcher Ben Novak, ”How to Bring Passenger Pigeons All the Way Back.” To Novak and others, re-creating the species could help revive not only their forest ecosystems but also our dwindling faith in human benevolence. Books also abound that tell the birds’ tragic extinction tale, including Elizabeth Kolbert’s riveting best-seller, The Sixth Extinction: An Unnatural History, and the moving elegy to multiple avian lossesHope Is the Thing With Feathers: A Personal Chronicle of Vanished Birds, by Christopher Cokinos. But for those who want to delve deeply into the historical and cultural relationships between pigeons and people, the authoritative work is Joel Greenberg’s A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction. Greenberg’s decades of dedication to unraveling ecological and cultural mysteries (photos of the birds, living or dead, remain elusive) enables him to explain the here-to-for inexplicable destruction of such a vast population in only about 40 years. here about flights that once blocked out the sun for days and the message they’ve left for future conservationists.