Cornell Laboratory of Ornithology. "All About Birds." Accessed March 29, 2012.
Smithsonian Institution. Encyclopedia Smithsonian. Accessed March 29, 2012.
University of Pittsburgh. Audubon's Birds of America at the University of Pittsburgh. Accessed March 29, 2012.
Earth Day: Lost to History
Human activity changes the lives of more than just human beings. Humans domesticate animals, hunt them for food and sport, introduce them to new territory—and even wipe them out entirely. In the quiz, match each North American bird to the year when the last known specimen died.