Northern Prairie Wildlife Research Center
This study has been an intermittent effort since 1975 and would have expired somewhere along the way had it not been for the generous support of the following organizations: Morgan Library, Colorado State University, Fort Collins, for help with references and interlibrary loans; U.S. Fish and Wildlife Service Denver Wildlife Research Center and Columbia National Fisheries Research Laboratory—Denver, for literature search and field reports.
Herbarium records, information, advice, or field support were supplied by
We are also grateful to more than 75 persons for advice, help, or information, especially L. Andres, S. Batra, F. Bellrose, P. Boldt, T. Bookhout, S. Brezinski, H. Brumsted, R. Clark, G. Cole, C. Dane, L. Davis, N. Dawe, V. Dewey, J. Elder, G. Gavutis, F. Golet, M. Hall, C. Hardy, B. Harper, F. Helmer, T. Jackson, R. Jones, H. Kano, E. Kiviat, E. Kivisalu, R. Malecki, P. Mann, K. Menzel, H. Miller, J. Morse, E. Moses, J. Mullan, A. Nice, T. Nigus, N. Norton, A. Notestein, H. O'Connor, M. Olson, M. Phillips, B. Popelka, T. Rawinski, P. Reed, M. Richmond, C. Robbins, J. Seubert, R. Sleeper, R. Streeter, S. Taylor, D. Thompson, D. B. Thompson (graphics), D. Tiller, L. Van Druff, D. Wade, W. Willen, S. Williams, E. Woehler, and J. Zimmerman.
Finally, we thank the New York Cooperative Wildlife Research Unit for providing the funds to publish this report.