Chandler Seymour Robbins was an American ornithologist. His contributions to the field include co-authorship of an influential field guide to birds, as well as organizing the North American Breeding Bird Survey.

Ludlow Griscom was an American ornithologist known as a pioneer in field ornithology. His emphasis on the identification of free-flying birds by field marks became widely adopted by professionals and amateurs. Many called him "Dean of the Birdwatchers."