Patterns of Distribution and Abundance of Breeding Colonial Waterbirds in the Interior of California, 2009–2012 1 November 2014 Report to: California Department of Fish and Wildlife Wildlife Branch – Nongame Wildlife Program 1812 9th Street Sacramento, CA 95811 and U.S. Fish and Wildlife Service, Region 8 Migratory Bird Program 2800 Cottage Way Sacramento, CA 95825 W. David Shuford Point Blue Conservation Science 3820 Cypress Drive # 11 Petaluma, CA 94954 Author contact information: W. David Shuford Point Blue Conservation Science 3820 Cypress Drive #11 Petaluma, CA 94954
[email protected] www.pointblue.org Cover photo: Multi-species colony, dominated by American White Pelicans (Pelecanus erythrorhynchos) and Ring- billed and California gulls (Larus delawarensis and L. californicus), on a large rocky islet in the east lobe of Clear Lake National Wildlife Refuge, Modoc County, California. Photo, 18 May 2009, by the author. Recommended citation: Shuford, W. D. 2014. Patterns of distribution and abundance of breeding colonial waterbirds in the interior of California, 2009–2012. A report of Point Blue Conservation Science to California Department of Fish and Wildlife and U.S. Fish and Wildlife Service (Region 8). Available at www.fws.gov/mountain- prairie/species/birds/western_colonial/. CONTENTS Acknowledgments…………………………………………………………………………………v Executive Summary…………………………………………………………………………….…1 Introduction………………………………………………………………………………………..3 Study Area and Methods…………………………………………………………………………..4 Background and Overall Approach…………………………………………………….….4