Massachusetts Audubon Society.
The American Bird Conservacy, a newly-formed political advocacy group intended to mobilize birdwatchers as a constituency.
the American Birdwatching Association.
Janet Egan's Piping Plover Page. Includes a diary describing her recent years as a Warden at the Parker River Refuge, along with an extensive list of interesting and useful links.
A pageful of plover links from Dick & Jean Hoffmann.
The Plum Island Hawk Watch.