We would like to thank Jim and Nadia Lane and the Wait family for their personal support during our field studies on the hawk owl in Manitoba and while this account was being prepared. Katherine McKeever, Robert Nero, and C. Stuart Houston kindly reviewed the manuscript and provided many insightful comments. We are grateful for the unpublished data, and access to specimens and records, provided by: Alaska Department of Fish and Game; Arctic Institute of North America; Association Québecoise des Group D'Ornithologues; Banff National Park, Canadian Parks Service; Calgary Parks and Recreation; Canadian Museum of Nature; Cowan Vertebrate Museum; Kamloops Wildlife Park; Manitoba Department of Natural Resources; Manitoba Museum of Man and Nature; The Nature Conservancy; Newfoundland Wildlife Division; Nova Scotia Natural Resources; Oregon Department of Fish and Wildlife; Owl Rehabilitation Research Foundation; Provincial Museum of Alberta; Québec Ministére du Loisir, de la Chase et de la Peche; Royal Saskatchewan Museum; U.S. Department of Interior, National Park Service; U.S. Department of Interior, Fish and Wildlife Service; University of Alaska; University of Alberta Museum of Zoology; University of British Columbia; University of Manitoba Zoology Museum; University of Michigan; University of Montana; University of Saskatchewan; and Western Foundation of Vertebrate Zoology.
We are very thankful to those who forwarded observations of hawk owls for inclusion in this account; they included: S. Ambrose, Norman Barichello, Al Benoit, Gary Bortolotti, Robert Bromley, Tim Cameron, R. Wayne Campbell, Richard Cannings, I. Carruthers, Doug Collister, Herbert Copland, Scott Crocoll, Jennifer Deaton, Heather Dempsey, Frank Doyle, David Evans, Denis Fast, Ilay Ferrier, Terry Galloway, C. Garber, Jean Gauthier, Robert Gehlert, B. Geisler, A. Gilyason, Steve Gniadek, Michel Gosselin, Wayne Harris, Janet Hinshaw, C. Stuart Houston, Darrell Hutchinson, Paul James, Joel Jehl, Jr., Bruce Johnson, David Johnson, Guy Jolicoeur, K. Kaufman, Lloyd Kiff, Janice Klapeki, Saskia Koning, Jacques Larivée, Randy Lauff, Michel Lepage, Steve Loch, Andrea MacCharles, Jeff Marks, John Maunder, Donald McAlpine, Mabel McIntosh, Carol McIntyre, Katherine McKeever, Ian McLaren, Dave Mossop, Bill Munro, Robert Nero, Timothy Osborne, Shirley Peruniak, Harold Pinel, Mac Pitcher, Erhard Pletz, Steve Quiney, Brian Ratcliff, Wayne Roberts, Christoph Rohner, L. Ronning, D. Russell, R. Russell, Peter Scott, Spencer Sealy, Carolyn Seburn, Alan Smith, E. Smith, Geir Sonerud, Tim Sopuck, Mark Steinhilber, Ted Swem, Peter Taylor, B. Vissers, Harry Walker, Rob Walker, Shan Walshe, Ulrich Waterman, Robert Wheeldon, and Steve Wilson. Alan Poole, Kenn Kaufman, Louis Bevier, and Keith Russell greatly improved the manuscript.