Western Riverside County Multiple Species Habitat Conservation Plan Biological Monitoring Program 2013 Northern Goshawk (Accipiter gentilis) Survey Report 25 July 2014 2013 Northern Goshawk Survey Report TABLE OF CONTENTS INTRODUCTION .............................................................................................................. 1 GOALS AND OBJECTIVES ............................................................................................................... 2 METHODS ......................................................................................................................... 4 SURVEY DESIGN ........................................................................................................................... 4 FIELD METHODS ........................................................................................................................... 4 TRAINING ...................................................................................................................................... 8 DATA ANALYSIS ........................................................................................................................... 8 RESULTS ........................................................................................................................... 8 DISCUSSION ..................................................................................................................... 9 RECOMMENDATIONS ................................................................................................................... 11 ACKNOWLEDGEMENTS .............................................................................................. 12 REFERENCES ................................................................................................................. 12 LIST OF TABLES AND FIGURES Figure 1. Northern Goshawk Bioregions designated by the MSHCP and incidental detection of goshawk in Wilson Valley in 2010.................................................................................................................................3 Figure 2. Northern Goshawk survey polygons and survey stations within each polygon in northern San Jacinto Mountains Bioregion in 2013 ..............................................................................................................5 Figure 3. Northern Goshawk survey polygons and survey stations within each polygon in central San Jacinto Mountains Bioregion in 2013 ..............................................................................................................6 Figure 4. Northern Goshawk survey polygons and survey stations within each polygon in southern San Jacinto Mountains Bioregion (Thomas Mountain) in 2013 .............................................................................7 Table 1. Number of stations surveyed by polygon and survey round .............................................................9 LIST OF APPENDICES Appendix A. Northern Goshawk survey data sheet ...................................................................................... 15 Appendix B. Avian species detected during Northern Goshawk surveys in 2013 ....................................... 16 Western Riverside County MSHCP ii Biological Monitoring Program 2013 Northern Goshawk Survey Report NOTE TO READER: This report is an account of survey activities conducted by the Biological Monitoring Program for the Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP). The MSHCP was permitted in June 2004. Reserve assembly is ongoing and is expected to take 20 or more years to complete. The Conservation Area includes lands acquired under the terms of the MSHCP and other lands that have conservation value in the Plan Area (called public or quasi-public lands in the MSHCP). In this report, the term “Conservation Area” refers to these lands as they were understood by the Monitoring Program at the time the surveys were conducted. The Monitoring Program monitors the status and distribution of the 146 species covered by the MSHCP within the Conservation Area to provide information to Permittees, land managers, the public, and the Wildlife Agencies [i.e., the California Department of Fish and Wildlife (CDFW, formerly California Department of Fish and Game) and the U.S. Fish and Wildlife Service]. Monitoring Program activities are guided by defined conservation objectives for each Covered Species, other information needs identified in MSHCP Section 5.3 or elsewhere in the document, and the information needs of the Permittees. A list of the lands where data collection activities were conducted in 2013 is included in Section 7.0 of the Western Riverside County Regional Conservation Authority (RCA) Annual Report to the Wildlife Agencies. The primary author of this report was the 2013 Northern Harrier Project Lead, Masanori Abe. This report should be cited as: Biological Monitoring Program. 2014. Western Riverside County MSHCP Biological Monitoring Program 2013 Northern Goshawk (Accipiter gentilis) Survey Report. Prepared for the Western Riverside County Multiple Species Habitat Conservation Plan. Riverside, CA. Available online: http://www.wrc-rca.org/library.asp. While we have made every effort to accurately represent our data and results, it should be recognized that data management and analysis are ongoing activities. Readers wishing to make further use of the information or data provided in this report should contact the Monitoring Program to ensure that they have access to the best available or most current data. Please contact the Monitoring Program Administrator with questions about the information provided in this report. Questions about the MSHCP should be directed to the Executive Director of the RCA. Further information on the MSHCP and the RCA can be found at www.wrc-rca.org. Contact Information: Executive Director Western Riverside County MSHCP Western Riverside County Monitoring Program Administrator Regional Conservation Authority c/o Adam Malisch Riverside Centre Building 4500 Glenwood Drive, Bldg. C 3403 10th Street, Suite 320 Riverside, CA 92501 Riverside, CA 92501 Ph: (951) 248-2552 Ph: (951) 955-9700 Western Riverside County MSHCP iii Biological Monitoring Program 2013 Northern Goshawk Survey Report INTRODUCTION The Northern Goshawk (Accipiter gentilis; goshawk) is one of 45 bird species covered by the Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP) and is designated as a species of special concern at the state and federal levels (Dudek & Associates 2003; Squires and Kennedy 2006). The Plan lists three species- specific objectives. Objective 1 requires that at least 34,020 ac (13,767 ha) of suitable nesting and wintering habitat be conserved in deciduous woodland and montane coniferous forest within the Plan Area, specifically in the San Jacinto Mountains and San Bernardino Mountains Bioregions (Dudek & Associates 2003). Objective 2 specifies that the two known nesting locations shall be buffered from human disturbance by a 250-m radius during the breeding season and at least 1.6 sq. km of suitable nesting habitat will be conserved around each nest site. The same protection will be given to any additional nesting locations identified in the future. Objective 3 requires the continued use of, and successful reproduction at ≥75% of known nesting localities at least once every three years (Dudek & Associates 2003). Goshawks are widely distributed in the temperate zone of the northern hemisphere. In North America, the species inhabits and breeds in most areas except the south-central and southeastern parts of the U.S. (Squires and Reynolds 1997). In California, goshawks are common forest inhabitants in the north and within the Sierra Nevada, but they are extremely rare south of the Sierra Nevada (Keane 2008). The number of goshawks rapidly declined in the 20th century, primarily due to habitat loss associated with logging, agriculture, and urban development (Squires and Kennedy 2006). However, the estimates of goshawk population trends in the U.S. are poorly understood because of the difficulty of detecting individuals during long-term population surveys such as the Breeding Bird Survey (Keane 2008). Throughout the Sierra Nevada and northern California, Keane (2008) estimated there were approximately 1,000 breeding pairs between 1970 and 2000, but fewer than 20 breeding attempts were reported in southern California from 1958-2008. Goshawks in southern California typically nest in mature deciduous forest and montane coniferous forest from 2,000 to 2,700 m in elevation (Garrett and Dunn 1981). Within our Bioregions, the dominant tree species that goshawks previously used for nesting, foraging, and wintering were canyon live oak (Quercus chrysolepis) and California black oak (Q. kelloggii) in deciduous woodlands, and Jeffrey pine (Pinus jeffreyi), white fir (Abies concolor), and California incense-cedar (Calocedrus decurrens) in montane coniferous forest. High canopy closure and open understory are the most uniform characteristics of goshawk nest sites (Squires and Kennedy 2006). Goshawks may use areas with canopy cover <60%, but occupancy rates tend to increase with denser canopy cover (Reynolds et al. 1982; Hayward and Escaño 1989). Nest-stand sizes and home ranges are variable, approximately 10–100 ha and 570–3,500 ha, respectively (Reynolds et al. 1982; Woodbridge and Detrich 1994; Squires and Reynolds 1997). Goshawks usually have 1–5 alternative nest areas within a territory and they are an
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