The various species of new world blackbirds, often intermingled in large foraging flocks and nighttime roosts, collectively number in the hundreds of millions and are a dominant component of the natural and agricultural avifauna in North America today. Because of their abundance, conspicuous flocking behavior, and feeding habits, these species have often been in conflict with human endeavors.

The pioneering publications on blackbirds were by F. E. L. Beal in 1900 and A. A. Allen in 1914. These seminal treatises laid the foundation for more than 1,000 descriptive and...