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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-91 The presence of new transmission line 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 2c would require an estimated 124 structures in a landscape dominated by low growing grasses and shrubs. An estimated 60 of the new structures would be located greater than 0.25 mile from an existing transmission line or trees (Table 4.3-5). Within one mile of Route Segment 2c, potentially suitable habitat is present for 35 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 one mile of Route Segment 2c include elk winter range burrowing owl nests and breeding long-billed curlews. All 18.1 miles of Route Segment 2c are within the Rattlesnake Elk Winter Range Regular Concentration area. RDFs to minimize impacts to elk will include a seasonal restriction on construction. Specifically construction would be avoided during the wintering season, typically December 1 through March 1, or as defined by WDFW for each big game population in question (Section 2.3). The avoidance RDF is anticipated to be effective at minimizing impacts to elk; therefore, impacts are expected to be low for the entire 18.1-mile long route segment. Three burrowing owl nests were documented within one mile of Route Segment 2c in 2000. While these particular nests are not likely to have persisted to the present, it demonstrates potential for burrowing owls to nest within one mile of Route Segment 2c. 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. Additional impacts to burrowing owls could occur from the mechanical disturbance or crushing of burrows. Noise from construction equipment and general construction activities could disturb and displace individuals on a short-term basis with little impact. Long-term impacts would be related to loss of foraging habitat, reduction in preferred habitat for prey species, and disturbance or mortality from vehicle strikes or interactions with other equipment used for maintenance. If an occupied burrowing owl nesting site is found within 0.25 mile of the proposed route segment’s ROW, 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 5.3 miles and low for 12.8 miles. A long-billed curlew nesting area has been documented approximately 0.4 mile from Route Segment 2c. Additional suitable habitat is present. Impacts to long-billed curlew include a reduction and degradation of habitat, disturbance during nesting and brood-rearing periods, increased human activity, introduction and spread of noxious weeds, and injury or mortality due to collision with construction equipment. RDFs that would be implemented include closing access roads not required for ongoing maintenance activities, reseeding disturbed areas, implementing a noxious weed control plan, adherence to reasonable speed limits, and employing seasonal restrictions and buffers to avoid nesting long-billed curlews. Impact levels are expected to include 18.1 miles of low impacts for long-billed curlews. A majority of the habitat disturbance associated with Route Segment 2c is within the Regularly Occupied Habitat MU for Sage-Grouse, with the remainder occurring in Occasionally Occupied Habitat MU. Construction activities would disturb less than one percent of Regularly Occupied Habitat (Table 4.3-7). Approximately eight miles of this route segment borders JBLM YTC’s southern boundary. Habitat along this route segment is fragmented by roads, developed land, agricultural/cropland, and annual grass establishment. The eastern portion of this route segment parallels two existing transmission lines for