MOU -- Minnesota Ornithologists' Union publishes The Loon. Most states have their own birding organizations.
AOU -- American Ornithologists' Union, the premier national organization, publishes the AUK
COOPER ORNITHOLOGICAL SOCIETY --publishes the CONDOR
WILSON ORNITHOLOGICAL SOCIETY --publishes the WILSON BULLETIN
BRITISH ORNITHOLOGISTS' UNION --publishes the IBIS
THE AMERICAN BIRDING ASSOCIATION-- publishes BIRDING and tends to be aimed for birders rather than for scientists.