The American Ornithologists' Union (AOU) is "the oldest and largest organization in the New World devoted to the scientific study of birds". The AOU North American Classification Committee (NACC) maintains a checklist of North and Middle American Birds for which updates are regularly published.
The geographic area covered includes North and Central America from the boundary of Panama and Colombia northwards and including Hawaii, Bermuda and the West Indies. It is thus significantly larger than the area covered by the ABA list.
The most recent update incorporated in BUBO Listing was the 53rd supplement published in The Auk, Vol 129, pp573-588 (2012). This update has not been fully incorporated though: although species additions and deletions have been done, there were several changes to English and scientific names, and many changes to systematic order and the families to which species were assigned, that have not yet been processed.