Acknowledgments

This account would be very different without the work of the late J. K. Lowther, who discovered the polymorphism and negative assortative mating of White-throated Sparrows, and the late H. B. Thorneycroft, who discovered the chromosomal polymorphism that underlies these unique features. We are grateful to these and other graduate students, post-doctoral associates, and research assistants who have worked with us on this species from 1957 to the mid 1990s. These studies were supported mainly by grants from the Natural Sciences and Engineering Research Council of Canada and the National Research Council. We thank the staffs of Algonquin Provincial Park, Ontario and the Wildlife Research Station for the opportunity and facilities made available. We thank D. J. Loncke, K. C. Hannah, B. M. Horton, D. L. Maney, S. Ramsay and E. M. Tuttle for allowing us to cite their unpublished data. B. M. Horton and E. M. Tuttle sent us their doctoral theses providing data from Bradley, Maine and Adirondack Park, N.Y., respectively.

We are grateful to all who assisted in various ways. W. H. Piper and R. H. Wiley reviewed the account of winter behavior. B. M. Horton and D. L. Maney helped with the account of endocrine differences between morphs. J. D. Rising provided information and advice on distribution. S. L. Gaunt of the Borror Laboratory of Bioacoustics and A. L. Lang of the Royal Ontario Museum produced sonograms. L. F. Kiff and the Western Foundation of Vertebrate Zoology provided nest and egg data. T. L. Crewe provided data from the Canadian Migration Monitoring Network, while D. J. T. Hussell and J. D. McCracken provided data from the Long Point Bird Observatory. S. Ramsay helped review the literature. E. A. Falls assisted greatly with the preparation of the manuscript. Thanks also to the BNA staff for patient and helpful editing.