The American Ornithologist Society (AOS)
With the merger of the American Ornithologists’ Union (AOU) and the Cooper Ornithological Society (COS), the American Ornithological Society was formed.
From their website at americanornithology.org:
The American Ornithologists’ Union (AOU) was founded in 1883 out of concern for bird conservation and interest in developing the field of ornithology in North America. Early AOU efforts led to formation of the National Audubon Society and the Biological Survey (now known as the U.S. Fish and Wildlife Service). Before merging with the Cooper Ornithological Society to form the American Ornithological Society in 2016 , the AOU was the largest ornithological society in the Western Hemisphere and one of the oldest organizations in the world devoted to the scientific study and conservation of birds.
The Cooper Ornithological Society (COS) commemorated an early western naturalist, Dr. James G. Cooper, and grew from a small band of naturalists in 1893 to an internationally recognized scientific society. The COS was committed to advancing the conservation and management of bird species by applying high-quality science, grounded in natural history, to our understanding of avian biology.
Effective 11 October 2016, these two societies merged to form the American Ornithological Society (AOS) and this is a quote from their website:
The AOS is a diverse, global network of empowered professionals, working together to advance the scientific study and conservation of birds. The world’s largest international ornithological society, the AOS is more relevant today than ever, and we’re dedicated to supporting the scientists doing this critical work – for the sake of birds, humanity and the planet.
Click on this link: The American Ornithological Society