The story of the last Passenger Pigeon and the disappearance of the Great Auk, Carolina Parakeet, and Heath Hen reveal the fragile connections between species and their environment. To help tell their story, the Smithsonian Libraries, Biodiversity Heritage Library, and the National Museum of Natural History have curated a joint exhibit entitled Once There Were Billions: Vanished Birds of North America which opened June 24 in the National Museum of Natural History.
