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Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration 72 Bank Swallow (Riparia riparia) The Bank Swallow is listed as Threatened under CESA. It is a small brown and white songbird with a small bill, long wings, and a dark breastband contrasting with a white chin and belly (Garrison 1999). This species is a neotropical migrant that breeds across North America, Europe, and Asia and winter in Central and South America and Africa (Garrison 1999). Approximately 70 - 90 % of the breeding population in California is dependent on habitats which occur along the Sacramento and Feather Rivers (Humphrey and Garrison 1986, Garrison et al. 1987, CDFW 1992). Breeding habitat includes riparian, lacustrine, and coastal areas with vertical banks, bluffs, cliffs, and occasionally sand quarries, with fine- textured or sandy soils (Garrison et al. 1987, Bank Swallow Technical Advisory Committee 2013). The species is dependent on bank erosion from high winter river flows to create suitable burrow substrate (Garrison 1999, Garrison 2004, Moffat et al. 2005). Bank Swallow forages predominantly over open riparian areas but also over brushland, grassland, wetlands, water, and cropland. Bank Swallow nests in colonies ranging in size from 3 to over 3,000 nest burrows, with nests placed in burrows dug into vertical banks (Bank Swallow Technical Advisory Committee 2013). Breeding occurs from April through June (CDFW 1999f). Bank Swallow has a low potential to occur within the Study Area due to no suitable nesting habitat present in the Study Area, although the species has been observed foraging in the vicinity. Implementation of Mitigation Measure MM BIO- 1 would reduce potential impacts to Bank Swallow to: Less than Significant with Mitigation Incorporated. Yellow Warbler (Setophaga petechia) Yellow Warbler is a California Species of Special Concern and a USFWS Bird of Conservation Concern. Yellow Warbler is a small, bright yellow bird with yellow- green back, round head and beady black eyes; males have chestnut streaks on the breast. The species is a Neotropical migrant that breeds throughout the northern portions of North America, extending into southern mountain ranges; the species historically occurred throughout California, but is now largely restricted to the coast and Sierra Nevada (Heath 2008). Yellow Warbler is a riparian obligate species that uses willow shrubs and thickets, and other riparian plants including cottonwoods, sycamores, ash, and alders. The species was once a common breeder in the Central Valley, but is largely extirpated in the Sacramento Valley, the Delta and San Joaquin Valley because of widespread habitat loss (Riparian Habitat Joint Venture 2004, Grinnell and Miller 1944). Recent breeding south of the Study Area on the San Joaquin River National Wildlife Refuge is largely attributed to riparian habitat restoration (Dettling et al. 2012). Yellow Warblers consume insect prey by gleaning along slender branches and leaves of shrubs and small trees. The species is territorial; males sing from perches at the top of