Much of Charles Darwin's groundbreaking work as an evolutionary biologist stemmed from his study of birds. It is universally acknowledged that Darwin's observation of bird groups and species like the Galapagos finches, mockingbirds, and rock doves was critical to the development of his theories on natural selection, evolution, and sexual selection. The significant number of diverse birds that Darwin covered in his published works represents a most substantial ornithological contribution. His major books alone contain reference to and consideration of almost 500 bird species, as well as...