This monumental four-volume monograph presents the definitive scientific treatment of the avifauna of the Belgian Congo, based on decades of fieldwork, expedition material, and taxonomic revision. Including extensive species descriptions, distribution analyses, ecological observations, and hundreds of plates and maps, it remains one of the most comprehensive ornithological works ever produced for Central Africa. The set documents the birdlife of the Belgian Congo through systematic accounts, specimen records, measurements, comparative morphology, behavioral notes, and habitat descriptions. Each volume contains detailed plates, distribution maps, and keys for identification. The work synthesizes findings from major AMNH expeditions and preserves essential data for modern biodiversity research, historical biogeography, and African ornithology. James Paul Chapin (1889-1964) was an American ornithologist affiliated with the American Museum of Natural History. He participated in the Congo expeditions of the early 20th century and became one of the leading authorities on African birdlife. His long-term research, museum work, and extensive field documentation established him as a cornerstone figure in African ornithology.