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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-111 NNR-6o, permanently disturbed areas would include 26.5 acres of sagebrush/perennial grassland; while for Route Segment NNR-6u, permanently disturbed areas would include 5 acres of sagebrush/perennial grassland (Table 4.3-4). RDFs would be implemented to minimize habitat loss and degradation, as described in Section 4.3.3.1. For either design option, impact levels to habitat are expected to be low for 2.3 mile and moderate for 4.1 miles (sagebrush/perennial grassland). The presence of new transmission structures, which could provide additional perch and/or nesting sites for avian predators, could negatively impact nearby prey species such as small mammals and avian species, particularly when the new structures are built in an area where perching opportunities currently do not exist (i.e., greater than 0.25 mile from existing structures or trees). Construction of Route Segment NNR-6o would require an estimated 48 structures. None of the new structures would be located greater than 0.25 mile from an existing transmission line (Table 4.3-5). Although the Underground Design Option would not require transmission towers, at both transitions between aboveground and underground transmission, a transition station would be required, resulting in approximately 5.0 acres of disturbance at each transition station. Within one mile of Route Segment NNR-6o/NNR-6u, potentially suitable habitat is present for 36 special status wildlife species that are possible, likely, or known to occur (Tables 3.3-2, 3.3-3, and 3.3-7). Potential impacts and RDFs to address them are discussed in Sections 4.3.3.1 and 4.3.3.2. Species or wildlife resources that have been documented at specific locations within 1.0 mile of Route Segment NNR-6o/NNR-6u include a burrowing owl nest, Merriam’s shrew, and regular concentration areas of loggerhead shrikes and mule deer. A historic burrowing owl nesting site (last documented occupancy prior to 2000) occurs approximately 0.7 mile from Route Segment NNR-6o/NNR-u. While this particular nest is not likely to have persisted to the present, it demonstrates potential for burrowing owls to nest within one mile of Route Segment NNR- 6o/NNR-6u. Potential impacts would occur from disturbance during construction activities or from injury or mortality from vehicle strikes or interactions with other equipment used during construction, including mechanical disturbance or crushing of burrows. If an occupied burrowing owl nesting site is found within 0.25 mile of the proposed route segment, a seasonal restriction on construction would be enacted from March to August, within the 0.25-mile buffer. Additional RDFs to reduce impact on burrowing owls are described in Sections 4.3.3.1 and 4.3.3.2. Impact levels to burrowing owl are expected to be moderate for 0.6 mile. The McDonald Springs regular concentration of loggerhead shrikes is located approximately 0.9 mile from Route Segment NNR-6o/NNR-6u. Potential impacts include direct habitat loss, indirect habitat loss or degradation, increased predation from corvids and raptors attracted to nesting and/or perching opportunities on the new structures, and disturbance or displacement from noise or visual disturbance, especially during construction. RDFs would be implemented to minimize impacts, as described in Sections 4.3.3.1 and 4.3.3.2. Because the shrike concentration area is nearly 1.0 mile from the route segment, no identifiable impacts are anticipated. A Merriam’s shrew was documented within 1.0 mile of Route Segment NNR-6o/NNR-6u in 1954, demonstrating potential for Merriam’s shrews to exist within one mile of Route Segment NNR-6o/ NNR-6u. Potential impacts include habitat loss, habitat degradation, injury or mortality due to crushing by construction equipment or vehicles, and increased predation from avian predators. RDFs would be implemented to minimize impacts, as described in Sections 4.3.3.1 and 4.3.3.2. No identifiable impacts are anticipated. The south slopes of the Saddle Mountains have been identified as a mule deer regular large concentration area. While the PHS data does not specify a season of use for this area, the south-facing sagebrush-steppe