Birding Links

National Audubon Society

Wilson Ornithological Society
  http://www.ummz.lsa.umich.edu/birds/wos.html

Birding America

Fat Birder

American Birding Association

American Bird Conservancy

Birding.com
Birding.com is devoted to birding in the U.S. and around the world.
www.birding.com

SORA
(Searchable Ornithological Research Archive)
http://elibrary.unm.edu/sora/index.php

Cornell Ornithology Lab