The
American Ornithologists' Union (
AOU) is an
ornithological organization based in the United States. Its members are primarily professional ornithologists although membership is open to anyone with an interest in birds. The AOU is a member of the
Ornithological Council and Ornithological Societies of North America (OSNA). The Union publishes the scholarly journal
The Auk as well as the
AOU Checklist of North American Birds