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Home My WebLink AboutCT 98-14; Thompson/Tabata; Tentative Map (CT) (137)& ASSOCIATES, INC. Professional Teams for Complex Projects September 12, 2002 Bring, Planning, Environmental Sciences and Management Services Corporate Office: 605 Third Street Encinitas, California 92024 760.942.5147 Fax 760.632.0164 2755-02 Ms. Kathy Baker Standard Pacific Homes 5750 Fleet Street, Suite 200 Carlsbad, California 92008 SUBJECT: BURROWING OWL SURVEY FOR THE THOMPSON PROPERTY, CITY OF CARLSBAD Dear Kathy: A burrowing owl (Athene cunicularia) survey was conducted for the approximately 79.4-acre Thompson property within the City of Carlsbad, San Diego County, California during August 2002. The survey consisted of a presence/absence breeding survey within areas of suitable habitat and covered most of the property. PROJECT LOCATION AND EXISTING CONDITIONS The property is located west of El Camino Real, adjacent to Aviara Parkway, east of Interstate 5, south of Palomar Airport Road and north of Batiquitos Lagoon (Figures 1 and 2). Poinsettia Lane bisects the northern portion of the property from east to west. The property is surrounded by residential development with a strip of native vegetation located to the east. Biological surveys of the property were conducted in December 1997 and June 1998 by Dudek & Associates (DUDEK) to assess the general existing conditions of the biological resources. Based on species composition and general physiognomy, three plant communities (or habitat types) were identified within the Thompson property: coastal sage scrub, southern willow scrub, and disturbed habitat in the form of agriculture, developed land, and landscape plantings. The existing plant communities are described below. Table. 1 presents the acreage of each vegetation type present onsite. TABLE 1. EXISTING PLANT COMMUNITY ACREAGES PLANT COMMUNITY (ABBREVIATION USED ON MAP) Coastal Sage Scrub (CSS) Southern Willow Scrub (SWS) Disturbed Habitat (DH) TOTALS EXISTING ACREAGE 1.8 0.1 77.5 79.41 Ms. Kathy Baker Re: Burrowing Owl Survey for the Thompson Property, City of Carlsbad, California Coastal Sage Scrub Coastal sage scrub is a native plant community characterized by a variety of soft, low, aromatic, drought-deciduous shrubs, such as California sagebrush (Artemisia californica), flat- top buckwheat (Eriogonum fasciculatum), California bush sunflower (Encelia californica}, and sages (Salvia spp.), with scattered evergreen shrubs, including lemonadeberry (Rhus integrifolia), laurel sumac (Malosma laurina), and toyon (Heteromeles arbutifolia). It typically develops on south-facing slopes and other xeric situations. Coastal sage scrub is considered a sensitive habitat type because of its depleted nature and the large number of sensitive plant and wildlife species that it supports. Coastal sage scrub is the focus of the present State of California's Natural Communities Conservation Program (NCCP). Onsite, coastal sage scrub occurs along the eastern property line as a narrow band of habitat that continues offsite within the open space located between the property and Aviara Parkway. A total of 1.8 acres of coastal sage scrub is located onsite. The habitat is very diverse and is dominated by California sagebrush and includes flat-top buckwheat, California bush sunflower, black sage (Salvia mellifera], laurel sumac, lemonadeberry, prickly pear (Oyuntia littoralis), and other plant species. Patches of eucalyptus woodland occur within the open space area adjacent to the coastal sage scrub. Southern Willow Scrub Holland (1986) describes southern willow scrub as "dense, broadleafed, winter-deciduous riparian thickets dominated by several species of [willows] Salix, with scattered emergent [Fremont cottonwood") Populus fremontii and [western sycamore] Platanus racemosa." The understory is usually depauperate owing to the dense canopy. Within the property there is one patch of riparian habitat that are dominated by arroyo willow (Salixlasiolepis) and red willow (Salix laevigata) with tamarisk (Tamarix sp.) and giant cane (Arundo donax] also present. The patch of southern willow scrub is located along the western property boundary adjacent to the paved access road to the site. It appears to be located within a manmade water retention or desiltation basin. Non-native grasses are present along the edges of the basin which would likely also be considered the jurisdiction of the regulating agencies. A total of approximately 0.10 acre of southern willow scrub is located within the basin. Although the southern willow scrub habitat area is moderately 2755-02 & ASSOCIATES, INC. n „September 2002 Page 2Professionat Teams /or Complex Pr»j'«cts -"N Ms. Kathy Baker Re: Burrowing Owl Survey for the Thompson Property, City of Carlsbad, California disturbed, it is considered sensitive because it represents wetland habitat that is regulated by the California Department of Fish and Game. Disturbed Habitat For purposes of this document, disturbed habitat includes areas of agriculture production, developed areas that include paved roads and existing houses, pavement and buildings, and landscaped areas along the manufactured slopes of Poinsettia Lane and the housing developments along the property boundaries. Major portions of the property (77.5 acres) are comprised of disturbed habitat. Floral Diversity A total of 39 species of vascular plants were recorded from the site. The relatively low floral diversity of the area is the result of the large amount of disturbed habitat in the form of agricultural production onsite. METHODS The presence/absence breeding season survey for the burrowing owl was conducted on the project site on August 15, 20,26, and 30,2002 by DUDEK biologist Dr. Anita M. Hayworth (AMH). The survey was conducted following the currently accepted protocol of The California Burrowing Owl Consortium (Burrowing Owl Survey Protocol and Mitigation Guidelines; April 1993). The survey included a four visit survey to the all areas of the project at approximately five-day intervals. The first visit, in accordance with the survey protocol, identified the potential for suitable habitat or conditions for the presence of the species. That is, suitable soils with burrows from California ground squirrels or other mammals were searched for before deciding to conduct a full presence/absence survey. Once the suitable conditions for the presence of the burrowing owl was determined, the remainder of the presence/absence survey was conducted. All areas of the agriculture area and former greenhouse area were visited during each survey. The survey was conducted by walking through suitable burrowing owl habitat in a transect formation. The distance between the transect lines was no more than 100 feet. The route used to survey the habitat varied during each visit and was arranged to ensure complete coverage of the habitat. A 1"=200' aerial photograph of the property was available to map burrow or owl locations. Binoculars (10 x 2755-02 & ASSOCIATES, INC. „ „September2002 Page 3 TWs. Kathy Baker Re.- Burrowing Owl Survey fonhe Thompson Property, City of Carlsbad, California 40) were used to aid in detecting and identifying bird species. The weather conditions were generally pleasant and mild as shown in the table below. DATE August 15 August 20 August 26 August 30 PERSONNEL ! AMH AMH { AMH [ AMH TEMPERATURE 65'F I 61 • 72"F !1 72-74'F | 68-73'F |i WIND 13MPH 0-5 MPH 3-5 MPH 0-3 MPH SKY clear clear clear clear TIME 0610-0820 1610-1835 1640-1845 0710-0940 RESULTS No burrowing owls were observed during the breeding season survey of the Thompson property in August 2002. Presence of California ground squirrels was detected by the observation of burrows at the margins of the agriculture fields, however none of the burrows was excavated to the size that is required by burrowing owls, no evidence was observed (feces, pellets, feathers), and no owls were observed on the property. Very truly yours, DUDEK & ASSOCIATES, INC. Anita M. Hayw6rt/h, Ph.D. Biologist Attachments: Figures 1 and 2 & ASSOCIATES, INC. 2755-02 Pro/e»ional Teams for Complex Projec September 2002 Page 4 Lemon Grove National / <^ City 1"-8 Miles Tijuana Thompson Property Regional Map FIGURE BASE MAP SOURCE: USGS 7.5 Minute Series, Encinitas Quadrangle 1"=2000' Thompson Property Vicinity Map