The National Geographic Society supported much of the authors' plover research over the years. Additional funding (OWJ) was from the U.S. Fish and Wildlife Service, U.S. Geological Survey, Minnesota State University Moorhead, and Brigham Young University-Hawaii. Other sources (PGC) were the Bureau of Land Management and National Oceanic and Atmospheric Administration, as part of the Alaska Outer Continental Shelf Environmental Assessment Program (OCSEAP), and the U.S. Fish and Wildlife Service. We thank many individuals for assistance in the field, particularly Phillip Bruner, Andrea Bruner, Paul Brusseau, Nancy Brusseau, Shane Gold, Roger Goodwill, Ronald Kienholz, Joop Jukema, Mark Johnson, Lee Johnson, John Maron, and Sarah Griffin. Special recognition goes to the late Patricia Johnson for her contributions and assistance in all phases of OWJ's plover studies. Important field observations and other information concerning plovers in Alaska were provided by Robert Gill, Jr., and Brian McCaffery; and in Chukotka by Pavel Tomkovich. Lloyd Kiff furnished egg data from the collection of the Western Foundation of Vertebrate Zoology. Danny Bystrak sent banding records from the U.S. Geological Survey, Bird Banding Laboratory, and Edward Miller shared in-press material concerning vocalizations of plovers. We are indebted to the late Miguel Muñoz for his generous assistance in translation of Spanish literature. Michael Patten contributed to the Systematics section in the revised account. Special thanks to the librarians at Renne Library at Montana State University, who efficiently and cheerfully secured various, often obscure, publications.