Acknowledgments

I thank Kate Moitoret for considerable information about breeding biology from 5 years of field work in n. Alaska; Philippa Shepherd for information about foraging behavior; and Brian Harrington and Sarah Groves for census data and their unpublished manuscript on molt and migration. Anthony Amos, Bill Brown, Tom Hahn, Robert Janssen, Alvaro Jaramillo, Oscar Johnson, and Jay Withgott also provided valuable information from field studies. I thank Sandra Gaunt, who furnished sonograms; Lloyd Kiff, who furnished egg data; Danny Bystrak, who sent banding data; Robert Pyle, who sent Hawaiian records from the Bishop Museum Occurrence and Status Archive; and Gary Shugart and Chris Thompson, who assisted in obtaining references. Jim Erckmann helped me gather data on breeding biology on Victoria Island, and friends too numerous to name assisted me in the field in Washington. Oscar Johnson and Peter Stettenheim contributed greatly by their careful reviews of the manuscript.

I thank the following individuals for sending data on specimens in their care: David Agro, Academy of Natural Sciences of Philadelphia; George Baumgardner, Texas A&M University; Ralph Browning, National Museum of Natural History; Richard Cannings, Cowan Museum, University of British Columbia; Robert Cannings and Michael McNall, Royal British Columbia Museum; Carla Cicero, Museum of Vertebrate Zoology, University of California; Karen Cebra, California Academy of Sciences; Peter Colston, British Museum of Natural History; Kimball Garrett, Los Angeles County Museum of Natural History; Dan Gibson, University of Alaska Museum; Michel Gosselin, Canadian Museum of Nature; Gene Hess, Delaware Museum of Natural History; Janet Hinshaw, University of Michigan Museum of Zoology; Vickie Byre, Dan Hough, and Gary Schnell, University of Oklahoma Museum of Natural History; John Klicka, Bell Museum of Natural History, University of Minnesota; Thomas Labedz, University of Nebraska State Museum; Scott Lanyon, Field Museum of Natural History; Dennis Martin, Pacific Lutheran University; Kevin McGowan, Cornell University; Brad Millen, Royal Ontario Museum; Carla Nishitani, Bernice P. Bishop Museum; James Northern, Moore Laboratory of Zoology, Occidental College; Robin Panza and Kenneth Parkes, Carnegie Museum of Natural History; Raymond Paynter, Museum of Comparative Zoology, Harvard University; Van Remsen and Steven Cardiff, Louisiana State University Museum of Natural Science; Mark Robbins, University of Kansas Natural History Museum; Fred Sibley, Peabody Museum, Yale University; Philip Unitt, San Diego Natural History Museum; and Tom Webber, Florida Museum of Natural History, University of Florida.

I examined specimens in the Slater Museum of Natural History, University of Puget Sound; Burke Museum, University of Washington; and Conner Museum, Washington State University (thanks to Richard Johnson and Kevin Pullen).

Finally, I thank especially Netta Smith, who helped me acquire references, accompanied me in the field, and tolerated my long hours of dedication to a half-pound bird rather than herself.