U.S. Fish & Wildlife Service Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States Biological Technical Publication BTP-R6001-2003 © Michael Forsberg U.S. Fish & Wildlife Service Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States Biological Technical Publication BTP-R6001-2003 David S. Klute1,7 William H. Howe4 Steven R. Sheffield6,9 Loren W. Ayers2,8 Stephanie L. Jones1 Tara S. Zimmerman3 Michael T. Green3 Jill A. Shaffer5 1 U.S. Fish and Wildlife Service, Region 6, Nongame Migratory Bird Program, Denver, CO 2 Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming, Laramie, WY 3 U.S. Fish and Wildlife Service, Region 1, Nongame Migratory Bird Program, Portland, OR 4 U.S. Fish and Wildlife Service, Region 2, Nongame Migratory Bird Program, Albuquerque, NM 5 U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND 6 U.S. Fish and Wildlife Service, Office of Migratory Bird Management, Arlington, VA 7 Current Address: Colorado Division of Natural Resources 8 Current Address: Wisconsin Department of Natural Resources 9 Current Address: George Mason University Author contact information: For additional copies or information, contact: Nongame Migratory Bird Program David S. Klute, (Current address) Colorado Division U.S. Fish and Wildlife Service of Wildlife, 6060 Broadway, Denver, CO 80216. P.O. Box 25486 DFC Phone: (303) 291-7320, Fax: (303) 291-7456, Denver, CO 80225-0486 e-mail: [email protected]. Recommended citation: Loren W. Ayers, (Current address) Bureau of Klute, D. S., L. W. Ayers, M. T. Green, W. H. Howe, Integrated Science Services, Wisconsin Department S. L. Jones, J. A. Shaffer, S. R. Sheffield, and T. S. of Natural Resources, 101 S. Webster St., Madison, Zimmerman. 2003. Status Assessment and WI 53707-7921. Phone: (608) 261-6449, Fax: (608) Conservation Plan for the Western Burrowing Owl 266-5226, e-mail: [email protected]. in the United States. U.S. Department of Interior, Fish and Wildlife Service, Biological Technical Michael T. Green, U.S. Fish and Wildlife Service, Publication FWS/BTP-R6001-2003, Washington, Region 1, Nongame Migratory Bird Program, D.C. 911 Northeast 11th Avenue, Portland, OR 97232. Phone: (503) 231-6164, Fax: (503) 231-6164, e-mail: [email protected]. William H. Howe, U.S. Fish and Wildlife Service, Region 2, Nongame Migratory Bird Program, P.O. Box 1306, Albuquerque, NM 87103. Phone: (505) 248-6875, Fax: (505) 248-6674, e-mail: [email protected]. Stephanie L. Jones, U.S. Fish and Wildlife Service, Region 6, Nongame Migratory Bird Program, P.O. Box 25486 DFC, Denver, CO 80225-0486. Phone: (303) 236-4409, Fax: (303) 236-8680, e-mail: [email protected]. Jill A. Shaffer, U.S. Geological Survey, Northern Prairie Wildlife Research Center, 8711 37th St. SE, Jamestown, ND 58401. Phone: (701) 253-5547, Fax: (701) 253-5553, e-mail: [email protected]. Steven R. Sheffield, (Current address) Department of Biology, George Mason University, Fairfax, VA 22030, e-mail: srsheffi[email protected]. Tara S. Zimmerman, U.S. Fish and Wildlife Service, Region 1, Nongame Migratory Bird Program, 911 Northeast 11th Avenue, Portland, OR 97232. Phone: (503) 231-6164, Fax: (503) 231-6164, e-mail: [email protected]. ii Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States Table of Contents Table of Contents . iii List of Figures . vi List of Tables. viii Executive Summary . 1 Acknowledgments . 2 Taxonomy . 3 Legal Status . 4 United States . 4 Canada . 4 Mexico . 4 Description. 6 Distribution. 7 Breeding. 7 Migration . 7 Winter. 7 Natural History. 10 Breeding . 10 Phenology. 10 Diet . 10 Foraging . 10 Productivity . 10 Territory. 10 Aggregations . 10 Mortality and Predation . 11 Site and Burrow Fidelity. 11 Habitat. 12 Breeding . 12 Migration . 12 Winter. 12 Populations . 13 Population Estimates and Trends . 13 Breeding Bird Survey . 13 Christmas Bird Count . 13 Other Surveys, United States . 13 Other Surveys, Canada . 17 Other Surveys, Mexico . 17 Densities . 17 Changes in Breeding Season Distribution. ..