Black Oystercatcher (Haematopus bachmani) Statewide Reproductive Performance in California in 2012-2014 A. Laurie Harvey1, Anna Weinstein2, Katherine Krieger2 and Liling Lee2 1Sutil Conservation Ecology, 30 Buena Vista Avenue, Fairfax, CA 94930 USA 2Audubon California, 220 Montgomery Street, Suite 1000, San Francisco, CA 94104 USA FINAL REPORT Prepared for Audubon California 12 October 2017 Suggested citation: Harvey, A.L., A. Weinstein, K. Krieger, and L. Lee. 2017. Black Oystercatcher (Haematopus bachmani) statewide reproductive performance in California in 2012-2014. Unpublished report submitted to Audubon California by Sutil Conservation Ecology. 66 pp. Cover photo courtesy of H. Ceja. Table of Contents INTRODUCTION .......................................................................................................................... 6 METHODS ..................................................................................................................................... 7 RESULTS ....................................................................................................................................... 8 Overview of the 2012-2014 monitoring effort ............................................................................ 8 Table 1. Total linear kilometers of coastline surveyed in the six Black Oystercatcher monitoring regions in 2012-2014. ........................................................................................... 8 Figure 1. Overview map of Black Oystercatcher regional monitoring areas in California, 2012-2014. ............................................................................................................................... 9 Table 2. Survey effort as number of observers and survey hours in the six Black Oystercatcher monitoring regions, 2012-2014. ..................................................................... 10 Black Oystercatcher reproductive performance, 2012-2014..................................................... 10 Table 3. Sample sizes for Black Oystercatcher nest success calculations in 2012-2014 (total number of nest attempts, including replacement clutches).................................................... 10 Table 4. Black Oystercatcher nest success, 2012-2014, expressed as the percentage of nest attempts that fledged at least one chick. ................................................................................ 11 Figure 2. Black Oystercatcher nest success (percentage of attempts that fledged at least one chick) in the six regional monitoring areas, 2012-2014. ....................................................... 12 Table 5. Sample sizes used for Black Oystercatcher fledging success calculations (number of pairs with known outcomes) in 2012-2014. ...................................................................... 12 Table 6. Fledging Success expressed as total number of Black Oystercatcher chicks fledged per pair in 2012-2014. ........................................................................................................... 13 Figure 3. Black Oystercatcher fledging success at the six monitoring areas in 2012-2014. 13 Figure 4. Within-year comparisons of regional Black Oystercatcher average fledging success in 2012-2013. ............................................................................................................ 14 REGIONAL RESULTS. ........................................................................................................... 14 Mendocino County. ................................................................................................................... 14 Table 7. Total linear kilometers of coastline surveyed in the Mendocino County ................ 16 Black Oystercatcher monitoring region in 2012-2014. ......................................................... 16 Table 8. Sample sizes (individual pairs with known fates) for Black Oystercatcher fledging success calculations in the Mendocino monitoring area, 2012-2014. ................................... 16 Table 9. Black Oystercatcher fledging success (young fledged/pair) in the Mendocino monitoring area, 2012-2014. ................................................................................................. 17 Figure 5. Black Oystercatcher fledging success from thirteen areas in Mendocino County, 2012-2014. ............................................................................................................................. 17 Figure 6. Black Oystercatcher mean fledging success in Mendocino County in 2012-2014.18 Page 2 of 30 San Luis Obispo County (SLO) ................................................................................................ 18 Table 11. Sample sizes (individual pairs with known fates) for fledging success calculations in San Luis Obispo County Monitoring Area. ....................................................................... 19 Table 12. Black Oystercatcher productivity (young fledged/pair) in San Luis Obispo County Monitoring Area, 2012-2014. ................................................................................................ 20 Figure 7. Black Oystercatcher fledging success from seven areas in San Luis Obispo County, 2012-2014. ............................................................................................................... 20 Sonoma County. ........................................................................................................................ 20 Figure 8. Black Oystercatcher mean fledging success in the Sonoma County monitoring area in 2012-2014. ......................................................................................................................... 21 Monterey County....................................................................................................................... 22 Table 13. Total linear kilometers surveyed in the Monterey County monitoring locations in 2012-2014. ............................................................................................................................. 22 San Mateo County. .................................................................................................................... 22 San Francisco Bay Area ............................................................................................................ 23 Table 14. Total linear kilometers surveyed in the San Francisco Bay area Black Oystercatcher monitoring locations in 2012-2014. ............................................................... 23 Table 15. Sample sizes (individual pairs with known fates) for fledging success calculations in San Francisco Bay Area Black Oystercatcher monitoring area in 2012-2014. ................. 24 Table 16. Black Oystercatcher productivity (young fledged/pair) in San Francisco Bay Area monitoring areas, 2012-2014. ................................................................................................ 24 DISCUSSION ............................................................................................................................... 25 ACKNOWLEDGEMENTS .......................................................................................................... 26 LITERATURE CITED ................................................................................................................. 27 APPENDIX I. Overview map of California counties in which monitoring for Black Oystercatcher reproductive success occurred in 2012-2014. ........................................................ 28 APPENDIX II. Black Oystercatcher monitoring areas and individual nest sites located in 2012- 2014 in Mendocino County .......................................................................................................... 29 Figure 1. Overview map of Mendocino County monitoring areas in 2012. ............................. 29 Figure 2. Locations of individual nests in the Laguna Point (LP) and Glass Beach (GB) monitoring areas in Mendocino County, 2012. .......................... Error! Bookmark not defined. Figure 3. Locations of individual nests in the GP Mill (GP) and Noyo Harbor (NO) monitoring areas in Mendocino County, 2012.............................................. Error! Bookmark not defined. Figure 4. Locations of individual nests in the Point Cabrillo (PC) monitoring area in Mendocino County, 2012. .......................................................... Error! Bookmark not defined. Page 3 of 30 Figure 5. Locations of individual nests in the Russian Gulch (RG) monitoring area in Mendocino County, 2012. .......................................................... Error! Bookmark not defined. Figure 6. Locations of individual nests in the Mendocino Headlands (MH) monitoring area in Mendocino County, 2012. .......................................................... Error! Bookmark not defined. Figure 7. Locations of individual nests in the Spring Ranch (SR), and Little River (LR) monitoring areas in Mendocino County, 2012. .......................... Error! Bookmark not defined. Figure 8. Locations of individual nests in the Navarro Point (NP) monitoring areas in Mendocino County, 2012. .......................................................... Error! Bookmark not defined. Figure 9. Overview map of Mendocino County monitoring areas in 2013. ... Error! Bookmark not defined. Figure 10. Locations of individual nests in the Hardy Rock monitoring area in Mendocino County, 2013. ............................................................................. Error! Bookmark not