Emily Dickinson's poem "Split the Lark" refers to the "scarlet experiment" by which scientists destroy a bird in order to learn more about it. Indeed, humans have killed hundreds of millions of birds--for science, fashion, curiosity, and myriad other reasons. In the United States alone, seven species of birds are now extinct and another ninety-three are endangered. Conversely, the U.S. conservation movement has made bird-watching more popular than ever, saving countless bird populations; and while the history of actual physical human interaction with birds is complicated, our long aesthetic...