Another step towards the modern field guide happened in 1903, when ornithologist and curator at the American Museum of Natural History Frank Chapman worked with illustrator Chester Reed to produce a book whose sole aim was “the identification of the bird in the bush”. Their Color Key to North American Birds (available here through Project Gutenberg) was the first to rely on a visual approach to identification, rather than the lengthy, technical, and difficult to use taxonomic keys that collection-based ornithologists relied on. Each species was illustrated with a tinted ink drawing, executed not as works of expressive art, but as a symbolic and characteristic representation of what a bird generally looked like from a distance. Chapman also arranged his birds by their most obvious color or habits, rather than by taxonomic family and genus. The text was a condensed description of each bird’s plumage, voice, and range.
This book was a landmark; for the first time an expert had put together one book, specifically for bird-watchers, designed to aid identification in the field, primarily through illustrations, covering the birds of the entire continent north of Mexico. The shift from specimens to observation-from the dead bird to the living one, is demonstrated in its pages.