From June 24, 2014 – Jan 3, 2016, the Smithsonian Libraries presents “Once There Were Billions: Vanished Birds of North America”. The exhibition, on display in the National Museum of Natural History in Washington DC, focuses on the story of the last Passenger Pigeon, the disappearance of the Great Auk, Carolina Parakeet, and Heath Hen <a href="http://blog.library.si.edu/2015/01/once-there-were-billions-t-shirts-now-available/#more-'" class="more-link">more »</a>