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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-77 wrightii), cedar waxwing (Bombycilla cedrorum), sage thrasher (Oreoscoptes montanus), sage sparrow (Amphispiza belli), black-throated sparrow (Amphispiza bilineata), and Oregon vesper sparrow (Pooecetes gramineus affinis). The latter four species breed in relatively high densities in sagebrush- steppe and are likely to nest within the proposed ROWs of the Action Alternatives in shrubs or on the ground. Ground disturbance during the breeding season would have a high probability of destroying nests of these four songbird species causing direct mortality. For all four species nest failure is relatively common under natural conditions and the birds habitually renest within the same season if a nest fails. Direct mortality associated with construction is unlikely to have a significant impact on local population sizes of these species. Other impacts to special status upland bird species include direct habitat loss, indirect habitat loss, or degradation, increased predation from corvids and raptors attracted to nesting and/or perching opportunities on the transmission line structures, and disturbance or displacement from noise or visual disturbance, especially during construction. Habitat loss and degradation has the greatest potential to impact upland special status bird species; however, the amount of habitat loss resulting from the proposed Project will be relatively small. Total short- and long-term direct disturbance for all habitat types combined ranges from one to 120 acres, depending on the route segment (Table 4.3-4). The implementation of RDFs are anticipated to reduce impacts to special status upland bird species and include: avoiding construction during the breeding season or having biologists conduct clearance surveys to find nests and buffer each nest from disturbance until the nesting attempt is complete; maintaining intact vegetation wherever possible; minimizing the blading of native plant communities during construction, consistent with safe construction practices; utilizing overland travel where feasible; reseeding disturbed areas with certified weed-free land management agency-approved native and non- native species or seed for revegetation as detailed in the POD; utilizing certified weed-free materials (e.g., seed, borrow material, straw wattles, and bale barriers); washing all equipment before entering the Project area and when leaving areas where noxious weeds are present; closing and revegetating new or improved access roads that are not required for ongoing maintenance activities; implementing a noxious weed control plan; and adherence to reasonable speed limits. Segment-specific impact levels are discussed in Section 4.3.4. Mammals Ten special status mammal species are documented or likely to occur within the Project study area: black- tailed and white-tailed jackrabbits (Lepus californicus and L. townsendii), Merriam’s shrew (Sorex merriami), Townsend’s ground squirrel (Urocitellus townsendii), pallid bat (Antrozous pallidus), elk (Cervus canadensis), little brown myotis (Myotis lucifugus), bighorn sheep (Ovis canadensis), and two subspecies of mule deer: Columbian black-tailed deer (Odocoileus hemionus columbianus ; west of I-82) and Rocky Mountain mule deer (O. hemionus hemionus; east of I-82). The occurrence of five special status mammal species including Preble’s shrew (Sorex preblei), northwest white-tailed deer (Odocoileus virginianus ochrourus), spotted bat (Euderma maculatum), Townsend’s big-eared bat (Corynorhinus townsendii), and Washington ground squirrel (Urocitellus washingtoni) within the Project study area has not been documented and based on habitat specifications, these species are not likely to occur within the Project study area. Therefore, impacts to those five species are not discussed in the following sections. For all ten species that do or are likely to occur within the Project study area, habitat loss and degradation have the most potential to have a serious impact, particularly if wildfire causes the replacement of sagebrush-steppe and perennial grasses and forbs with the annual cheatgrass. However, the amount of habitat loss resulting from the proposed Project will be relatively small. Total short-term and long-term direct disturbance for all habitat types combined for a given route segment is anticipated to range from one to 120 acres, depending on the route segment (Table 4.3-4). RDFs will minimize spread of invasive weeds and avoid increasing wildfire risk (as described in Section 4.3.3.1). Collision with vehicles during construction is another potential impact on all ten mammal species. Townsend’s ground squirrels retreat into underground burrows when disturbed and Merriam’s shrews often utilize burrows as well. These species may be unable to avoid being crushed or buried by construction equipment if they occupy areas where construction causes ground disturbance. Nevertheless, because total area of ground disturbance will