San Diego River Restoration Project: Edgemoor Property Santee, California

Transcription

1 Protocol California Gnatcatcher Survey Report San Diego River Restoration Project: Edgemoor Property Santee, California February 2008 Prepared for U.S. Fish and Wildlife Service Carlsbad Field Office 6010 Hidden Valley Road Carlsbad, CA Prepared by HDR Engineering, Inc Balboa Avenue, Suite 200 San Diego, CA 92123

2 Protocol Gnatcatcher Survey Report TABLE OF CONTENTS 1.0 INTRODUCTION STUDY AREA LOCATION SURVEY METHODS AND LIMITATIONS HABITAT ASSESSMENT SURVEY RESULTS CONCLUSIONS AND RECOMMENDATIONS...7 Figures Figure 1. Regional Location...2 Figure 2. El Cajon USGS Quadrangle...3 Figure 3. Vegetation Communities...4 Figure 4. California Gnatcatcher Data Map...6 Tables Table 1. Focused Coastal California Gnatcatcher Survey Dates, Times, and Climatic Conditions...5 Appendices Appendix A Appendix B Avian Species Observed Site Photographs San Diego River Restoration Project i US Fish and Wildlife Service

3 Protocol Gnatcatcher Survey Report 1.0 INTRODUCTION This report details the results of a focused California gnatcatcher (Polioptila californica) (CAGN) protocol survey for the San Diego River Restoration (SDRR) Project area, Edgemoor Property. With the SDRR Project, Edgemoor property (project area) the County of San Diego proposes enhancement and creation of riparian habitat which may be used to provide mitigation for future development projects. CAGNs were initially observed during a biological survey and a wetland delineation survey performed by RECON consultants in 2002 and P&D consultants in An updated CAGN survey was performed by HDR in late 2007 on the Edgemoor property to determine if this federally listed threatened species occurs within the vegetation communities associated with the project area. 2.0 STUDY AREA LOCATION The project area is located in the City of Santee bound by Cuyamaca Street to the west, Magnolia Avenue to the east, and generally along the floodplain of the San Diego River (Figure 1). The project area falls within the United States Geological Survey El Cajon quadrangle (Figure 2). The entire project area encompasses 104 acres. This includes a 35.2-acre excavation/restoration area south of the San Diego River, an approximately 25-acre stock pile area north of the river, and 44 acres that will not be impacted by the project. The SDRR project would enhance riparian habitat which may be used to provide future mitigation for development projects. This would involve both habitat enhancement and creation. Habitat enhancement would improve riparian scrub/woodland and freshwater marsh by removing invasive species, cleaning up trash, and, if needed, replanting select areas with native plants. In addition, habitat creation would convert nonnative grassland, tamarisk scrub, and disturbed habitat into open water, riparian scrub/woodland, and freshwater marsh (Figure 3). Current land uses surrounding the proposed project location involve residential to the west, east, and north, including a community park to the north, a concrete block manufacturing facility to the northeast, and fallow agriculture and a commercial center to the south. Within the project area, there are approximately 6 acres of marginal CAGN habitat; i.e., baccharis scrub (BS) and tamarisk scrub (TS) with very small isolated patches of Diegan coastal sage scrub (DCSS). 3.0 SURVEY METHODS AND LIMITATIONS In accordance with the U.S. Fish and Wildlife Service (USFWS) current survey protocol for the CAGN, suitable DCSS and marginally suitable habitats such as BS and TS were surveyed. The survey was conducted by permitted biologist Nick Muscolino (TE ) and Eric Peffer in a supervised role. The protocol surveys within the study area were conducted at intervals of no less than seven calendar days; In addition, no more than 80 acres of suitable CAGN habitat was surveyed per session (Table 1). In accordance with the County of San Diego Multiple Species Conservation Plan (MSCP), three site visits were conducted. All accessible portions of the study areas that could potentially support CAGN habitat were surveyed on foot to allow for direct visual observation of the habitat within the site s property boundaries. The scientific nomenclature used in this report is from the following standard references: vegetation communities (Holland 1986) and birds (American Ornithologists' Union 2000). San Diego River Restoration Project 1 US Fish and Wildlife Service

4 Source: SanGIS; 2005 G:\Projects\201384P&D\19265Edgemoor\map_docs\mxd\CAGN\Regional_Edgemoor_LANDSCAPE.mxd Last Updated : MIRAMAR RESERVOIR SAN VICENTE RESERVOIR San Vicente Creek San Diego 52 SANTEE RECREATIONAL LAKES Santee hg Project Site 67 Lakeside LINDO LAKE LAKE JENNINGS San Diego River Bostonia Granite Hills 805 $ Miles 15 8 LAKE MURRAY La Mesa Casa de Oro-Mount Helix El Cajon 54 Casa de Oro-Mount Helix Regional Location FIGURE 1 California Gnatcatcher Survey, Edgemoor Property

5 Project Boundary Mile 1:24,000 $ Source: First Source; USGS El Cajon Quadrangle, Second Source; YYYY G:\Projects\201384PD\19265Edgemoor\map_docs\mxd\CAGN\CAGN_usgsQuad.mxd El Cajon USGS Quadrangle FIGURE 2 San Diego River Restoration Project, Edgemoor Property County of San Diego California Gnatcatcher Survey

6 Source: P&D Environmental, 2006 G:\Projects\201384P&D\19265Edgemoor\graphics\docs\permitting\VegCommunitiesCAGN.ai Last Updated : Feet Vegetation Communities FIGURE 3 San Diego River Restoration Project, Edgemoor Property County of San Diego California Gnatchatcher Survey

7 Protocol Gnatcatcher Survey Report Table 1. Focused Coastal California Gnatcatcher Survey Dates, Times, and Climatic Conditions Surveyors Survey Date Times Cloud Cover Temperature Winds N. Muscolino 27 November %-80% F 0-1 mph E. Peffer N. Muscolino E. Peffer N. Muscolino E. Peffer 4 December % F 0-2 mph 11 December %-15% F 0-4 mph While walking the survey routes (Figure 4), a CAGN-taped vocalization was played at each observation point to elicit a response from any birds within the area. The recording was played for 5-10 seconds from each observation point and was oriented towards suitable habitat. The recording was played a minimum of five minutes apart at a maximum of three times per observation point, until a CAGN was observed or there was no response. The CAGN vocalization was not played at observation points where corvids (i.e., common raven (Corvus Corax), American crow (Corvus brachyrhynchos), and western scrub jay (Aphelocoma californica) were present. The surveys consisted solely of a presence/absence survey; nest assessments were not conducted as part of this survey. The quality of the CAGN habitat on site was low quality. The plant communities surveyed consisted of TS, BS, non-native grassland (NNG), and small remnant pockets of DCSS (Figure 3). No medium to high quality CAGN habitat was observed. The surveys were conducted during morning hours (between 0800 and 1230 hours) under overcast to clear skies (85-0% cloud cover), with air temperatures between 56 and 78 Fahrenheit, and wind velocities between 0 and 4 miles per hour (Table 1). 4.0 HABITAT ASSESSMENT CAGNs primarily occupy DCSS. This vegetation community is made up of low, soft woody shrubs which are mostly drought-deciduous species that can live in Mediterranean conditions. The characteristic species observed in this vegetation community can include California sagebrush (Artemisia californica), flat-top buckwheat (Eriogonum fasiculatum), lemonade berry (Rhus integrifolia) and laurel sumac (Malosma laurina). Depending on the distribution of the habitat, the sub-dominants may include various sage (Salvia spp.), toyon (Heteromeles arbutifolia), deer weed (Lotus scoparius), among others. DCSS generally occurs within areas of low moisture content, such as gently rolling to steep xeric slopes, or clayrich soils. At higher elevations DCSS intergrades with several chaparral species including mission manzanita (Xylococcus bicolor) and chamise (Adenostoma fasciculatum). Within the Edgemoor site enough DCSS to support breeding CAGNs was not observed. With the Edgemoor site being located along the San Diego River, the majority of the site s habitat is dictated by the hydrology. The onsite habitats consist of southern willow scrub (SWS) (Appendix B, Photograph 1), southern willow riparian forest (SWRF), baccharis scrub (BS) (Appendix B, Photograph 2), non-native grassland (NNG) (Appendix B, Photograph 3), and tamarisk scrub (TS), eucalyptus woodland, fresh water marsh (FWM), fallow agriculture, and small pockets of low quality DCSS (Figure 3). San Diego River Restoration Project 5 US Fish and Wildlife Service

8 Magno Cottonwood Ave.. lia Ave Cuyamaca Mission Creek Source: Aerial, Landiscor; 2005, G:\Projects\201384&D\19265Edgemoor\map_docs\mxd\CAGN\CAGN_Data.mxd Last Updated : River Park! (! (! ( h g! ( Legend Feet $ Project Boundary California Gnatcatcher Observations Survey Route Observation Point h g! ( Pair Single California Gnatcatcher Data Map FIGURE 4 San Diego River Restoration Project, Edgemoor Property County of San Diego California Gnatcatcher Survey

9 Protocol Gnatcatcher Survey Report Low quality CAGN habitat observed on-site is made up of BS. BS onsite consists almost entirely of broom baccharis (Baccharis sarothroides) with a few individuals of California goldenbush (Ericameria ericoides) flat-topped buckwheat (Eriogonum fasciculatum) and field mustard (Hirshfeldia incana). Fairly large stands of TS occur on site. The TS habitat is a monoculture of various Tamarix species. Often this scrub follows major disturbance. This community is found in washes and other areas which have high evaporation rates contributing to alkaline conditions. Tamarisk is a strong phreatophyte and a prolific seeder which often out-competes native species in riparian corridors (Holland). Low quality TS provides foraging habitat for CAGNs on-site. SWS and SWRF are the two riparian habitats found on-site and are associated with the San Diego River. These two riparian communities are dominated by arroyo willow (Salix lasiolepis), mulefat (Baccharis salicifolia), and black willow (Salix gooddingii) On-site NNG is present in areas that were previously disturbed with the majority of the NNG located on the southern and eastern portion of the project site. The NNG observed consist of various brome grasses (Bromus sp.) and field mustard. 5.0 SURVEY RESULTS During the protocol surveys in the Edgemoor study area, CAGN activity was observed. Two individuals and a pair of CAGNs (four total) were observed during the November 27 th survey. The individuals were observed foraging on the fringes of the BS and riparian SWS. The pair was observed foraging in the TS south of the pond on-site. Two individual CAGNs were observed during the December 4 th survey. The first CAGN was observed at 1120 foraging in the SWS just south-east of the pond. The second CAGN was spotted at 1145 and was again foraging on the fringes of BS and SWS east of the on-site pond. CAGNs were not in their breeding plumage; therefore, the sex of each bird was not determined during the survey. No CAGNs were observed during the December 11 th survey. None of the CAGNs observed during the survey display any territorial behavior such as repetitive calling or posting up on tall perches. Due to the location of the CAGNs observed, it appears that three CAGN groups occur on-site (Figure 4). It is noteworthy that CAGNS were observed with blue-gray gnatcatchers (Polioptila caerulea) within the TS. Sympatric use of TS by several gnatcatcher species has been documented. (Hamilton, Howell Western Birds 2002) 6.0 CONCLUSIONS AND RECOMMENDATIONS The Edgemoor project area currently supports four CAGNs (Figures 4) located within low quality habitat (TS and BS habitats). These areas are located on the southern and eastern portion of the survey area. The low quality habitat and lack of territorial behavior observed during the surveys support the conclusion that CAGNs use the site for winter foraging grounds. The site does not support high quality habitat which is known to be used by nesting CAGN. Therefore, the potential for CAGNs to nest on site is low. Incidentally, CAGNs were not observed during numerous general biological surveys conducted during the 2007 season. San Diego River Restoration Project 7 US Fish and Wildlife Service

10 Protocol Gnatcatcher Survey Report It is recommended that clearing or grubbing of occupied DCSS occur outside of the breeding season (defined roughly as February 15 through August 15). If construction should occur during the breeding season, indirect impacts could occur through noise or lighting impacts. A preconstruction survey is recommended to locate active nests within the alignment. If active nests are located within the alignment, noise abatement is recommended through the installation of sound walls, set backs and/or earthen berms to an acceptable 60 db (a) noise level. Directional lighting and noise mufflers to minimize construction impacts are also recommended to avoid indirect impacts from nighttime construction. San Diego River Restoration Project 8 US Fish and Wildlife Service

11 APPENDIX A Avian Species Observed

12 Protocol Gnatcatcher Survey Report Appendix A Avian Species Observed Family Common Name Scientific Name Podicipedidae pied-billed grebe Podilymbus podiceps eared grebe Podiceps nigricollis Phalacrocoracidae double-crested cormorant Phalacrocorax auritus Ardeidae great egret Ardea alba cattle egret Bubulcus ibis Anatidae mallard Anas platryrhynchos ruddy duck Oxyura jamaicensis northern shoveler Anas clypeata Cathartidae turkey vulture Cathartes aura Accipitridae osprey Pandion haliaetus American kestrel Falco sparverius Cooper s hawk Accipiter Cooperii sharp-shinned hawk Accipiter striatus red-shouldered hawk Buteo lineatus red-tailed hawk Bueto jamaicensis white-tailed kite Elanus leucurus Northern harrier Circus cyaneus Rallidae American coot Fulica americana Laridae California gull Larus californicus Columbidae mourning dove Zenaida macroura rock dove Columba livia Apodidae white-throated swift Aeronautes saxatalis Trochilidae Ann s hummingbird Calypte anna Costa's hummingbird Archilochus costae Alcedinidae belted kingfisher Ceryle alcyon Picidae Downy woodpecker Picoides pubescens Nuttall s woodpecker Picoides nuttallii Tyrannidae black phoebe Sayornis nigricans Say's phoebe Sayornis saya western kingbird Tyrannus verticalis Corvidae scrub jay Aphelocoma coerulescens American crow Coruvs brachyrhynchos common raven Corvus corax Timaliidae wrentit Chamaea fasciata Aegithalidae bushtit Psaltriparus minimus Troglodytidae Bewick s wren Thryomanes bewickii Regulidae ruby-crowned kinglet Regulus calendula San Diego River Restoration Project A-1 US Fish and Wildlife Service

13 Protocol Gnatcatcher Survey Report Family Common Name Scientific Name Sylviidae California gnatcatcher Polioptila californica californica blue-gray gnatcatcher Polioptila caerulea Sturnidae European starling Sturnus vulgaris Parulidae yellow-rumped warbler Dendroica coronata Turdidae Western bluebird Sialia mexicana Emberizidae California towhee Pipilo crissalis song sparrow Melospiza melodia white-crowned sparrow Zonotrichia leucophrys Lark sparrow Chondestes grammacus Icteridae Western meadowlark Sturnella neglecta Great-tailed grackle Quiscalus mexicanus Fringillidae house finch Carpodacus mexicanus lesser goldfinch Carduelis psaltria San Diego River Restoration Project A-2 US Fish and Wildlife Service

14 APPENDIX B Site Photographs

15 Appendix B Site Photographs Protocol Gnatcatcher Survey Report Photo 1. Southern willow scrub on the west end of the project area. Photo 2. Baccharis scrub located on the project site adjacent to and west of Cottonwood Avenue. San Diego River Restoration Project B-1 US Fish and Wildlife Service

16 Protocol Gnatcatcher Survey Report Photo 3. Non-native grassland north of the San Diego River. San Diego River Restoration Project B-2 US Fish and Wildlife Service