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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-78 be relatively small, the potential to adversely impact population size of these species is small. For the other mammal species, collision risk would be minimized by adhering to reasonable speed limits during construction and maintenance. The potential for increased presence of avian predators could negatively impact populations of white-tailed and black-tailed jackrabbits, Merriam’s shrew, and Townsend’s ground squirrel. The proposed Project’s effect on avian predators depends on the Action Alternative. The effect of NNR Alternative on predators is anticipated to be relatively small because the Action Alternative closely follows an existing 230 kV line with similar structures with the exception of Route Segment Manastash Ridge (MR) 1 which would not be sited close to an existing transmission line. The big game species, elk, mule deer, and bighorn sheep, are sensitive to disturbance, particularly during parturition/calving/lambing and during winter when increased energy expenditure can negatively affect survival. WDFW’s Wenas Wildlife Area within the Yakima River Canyon and on the foothill slopes west of the canyon is an important wintering area for elk and mule deer (WDFW 2006b). As the designated elk and mule deer winter range barely overlaps the Project study area, construction disturbance would be unlikely to impact wintering populations within the Wenas Wildlife Area. The southeast portion of the Project study area is also winter range for elk (Route Segments 1c, 2a, 2b, 2c, 2d, 3a, and 3b). The area extending south from the Saddle Mountains and west from the Columbia River has been identified as a mule deer regular large concentration area (Route Segments 2d, 3b, 3c, NNR-6, and NNR-7). Another mule deer regular concentration area occurs on Wanapum Bench, immediately north of the Vantage Substation. Adherence to seasonal restrictions on construction activities within these areas should minimize disturbance impacts to elk and mule deer. A bighorn sheep population with roughly 200 to 300 animals inhabits the Wenas Wildlife Area particularly near cliffs along the Yakima River Canyon and nearby tributaries. Areas designated as year round and lambing habitat occur west of the Project study area, primarily west of the Yakima River. Area designated as bighorn sheep winter range overlaps portions of Route Segment NNR-3, as well as the southwestern end of Route Segments NNR-4 and MR- 1. These route segments cross designated winter range in two areas: on the steep slopes surrounding Burbank Creek and the steep slopes surrounding Lmuma Creek and its tributaries. Adherence to seasonal restrictions on construction activities within these areas should minimize disturbance impacts to bighorn sheep. Additional RDFs to minimize disturbance impacts are described in Section 4.3.3.2. Segment- specific impact levels are discussed in Section 4.3.4. 4.3.3.6 Local Critical Areas Local critical areas for wildlife include streams, lakes, and riparian areas; big game winter range, and priority habitats and species. Aquatic and riparian communities comprise a small portion of the Project area, but these communities are characterized by higher productivity and greater habitat and species diversity compared to adjacent uplands. Riverine and associated riparian areas include the Columbia and Yakima rivers, Lower Crab Creek, Lmuma, Burbank, Johnson, Foster, and Selah creeks. While the greatest amount of aquatic and riparian habitat occurs within Route Segments 1a/NNR-1, 2d, 3b, 3c, NNR-7, and NNR-8, all route segments have at least some aquatic and/or riparian habitat with the exception of Route Segments 2b and NNR-5. Impacts to these areas and RDFs to minimize impacts are described in Section 4.3.3.1 Habitat, Section 4.3.4 Impacts Specific to Route Segments, Section 4.2 Vegetation and Special Status Plant Species, and Section 4.14 Water Resources. The big game species, elk, mule deer, and bighorn sheep, are sensitive to disturbance, particularly during parturition/calving/lambing and during winter when increased energy expenditure can negatively affect survival. As previously stated, winter range for elk, mule deer, and bighorn sheep occurs within the Project study area in Route Segments 1c, 2a, 2b, 2c, 2d, 3a, 3b, 3c, NNR-3, NNR-7, and NNR-8. Impacts to these areas and RDFs to minimize impacts are described in Section 4.3.3.5 State-listed and Other Special Status Species: Mammals and in Section 4.3.4 Impacts Specific to Route Segments.