Birds of the World This link opens in a new windowBirds of The World contains 10,721 species accounts from every bird species in the world and is an entirely new scientific publication that merges and enhances content, data, multimedia, figures, and illustrations from four different ornithological volumes: Birds of North America (BNA), Neotropical Birds, Handbook of Birds of the World (HBW Alive), and Bird Families of the World.