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Vantage to Pomona Heights Chapter 3 230 kV Transmission Line Project FEIS Affected Environment PAGE 3-69 In the southern portion of the Project study area, Sage-Grouse 80 percent core and 95 percent population range substantially overlaps the other route segments associated with Alternatives A-G. Route Segment 2a is entirely within the core population range. Route Segment 2b has the next highest proportion of overlap with the core and 95 percent population ranges (41 percent in core, 84 percent in population range) followed by Route Segments 1b (18 and 73 percent) and 1c (14 and 73 percent), 2c (25 and 59 percent), and 2d (four and 14 percent). Acreages of core population range and 95 percent population range within the ROW and eight-mile wide analysis area are shown in Table 3.3-4 and described for each route segment (Section 3.3.5). A time-series of the three study periods reveals a southeastward shift in the YTC Sage-Grouse population range and core population range since 1989. It is beyond the scope of this document to speculate at length on possible causes of the shift, but it should be noted that the existing Pomona-Wanapum 230 kV transmission line was built in the early 1970s, more than 15 years before the earliest available Sage- Grouse location data. An examination of fire history at JBLM YTC (see Figure 3.3-6) does not suggest a relationship between fire history and the shift in Sage-Grouse distribution. The formerly occupied area suffered minimal burns relative to areas within the current core population range. The shift in Sage- Grouse distribution may have been influenced by JBLM YTC training maneuvers. Most of the Sage- Grouse range shift occurred during the 1993 to 1999 period in JBLM YTC Training Areas (TA)-15 and TA-16. According to JBLM YTC (personal communication, JBLM YTC 2014a), there was a period of heavy training maneuvers during the mid-1990s, with particularly high activity levels in TA-16. It is also possible that the population shift was not a response to any change in habitat or disturbance levels, but merely a response to population declines, such that if the TA-15 and TA-16 areas held inherently lower quality habitat to begin with relative to the core area, they simply may have been the first areas to be abandoned as the population declined from over 300 birds during the 1989-1993 period to approximately 200 birds during the most recent period. The population range during the most recent period (2012-2014) provides the most useful information for predicting Project impacts on the current grouse population. Nevertheless, the historic population ranges might be indicative of areas likely to be reoccupied in the future if the YTC Sage-Grouse population recovers and expands into currently unoccupied areas. Future occupancy is speculative in nature and would depend on a number of factors including wildfire occurrence, military training activities, and future habitat condition. Sage-Grouse Leks Active, inactive, and historical leks are shown in Table 3.3-5 and discussed in Section 3.3.4 for each route segment. Leks are classified by JBLM YTC as: 1) active - a lek with at least two male grouse observed displaying on at least two different days during the previous two years or, if not checked in the past two years, was active during the last year checked; 2) inactive - has been active sometime during the previous 10 years, but was not active during the past two years or in the last year checked; or 3) historical - a formerly active lek site in which no activity has been observed for the previous 10 years (JBLM YTC 2014b; SEE 2013). Lek complexes are defined as active leks within 1.8 miles of each other and have been used to estimate the YTC Sage-Grouse population size and trends (SEE 2013; Schroeder et al. 2000). Fifteen (15) lek complexes are known to occur within JBLM YTC, containing approximately 22 leks. Of the 15 lek complexes, two have not been attended by male Sage-Grouse since the early 1990s. Lek surveys are conducted on JBLM YTC on a yearly basis with priority given to areas with prior Sage-Grouse sightings during the breeding period and active, inactive and historic lek locations. It is unlikely that an undocumented major lek exists on JBLM YTC in searchable areas. Additional leks may be present on JBLM YTC in unsearchable areas (i.e., Central Impact Area) and on adjacent private lands (SEE 2015).