Vantage to Pomona FEIS Index 34 - Laserfiche WebLink

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Vantage to Pomona Heights Chapter 3 230 kV Transmission Line Project FEIS Affected Environment PAGE 3-59 Generally, sagebrush-steppe with a perennial grass understory has the best potential to provide year-round suitable habitat for Sage-Grouse. Other shrubland and grassland habitat types have some potential to provide suitable or marginal habitat during one or more seasons depending on surrounding habitat and site-specific characteristics. Suitability of habitat for Sage-Grouse depends on several site-specific factors, including: 1) sagebrush cover, 2) sagebrush height, and 3) cover, height, and species composition of forbs and perennial grasses (Stiver et al. 2010). Sage-Grouse habitat requirements vary seasonally and they often select different habitats during breeding, late brood-rearing and wintering seasons (Schroeder et al. 1999). Seasonal use habitats considered essential for maintaining healthy Sage-Grouse populations include: 1) breeding and early brood-rearing, 2) summer/late brood-rearing, and 3) wintering habitats. Breeding/Early Brood Rearing Habitat The breeding and early brood-rearing season is considered the most sensitive time of year for Sage- Grouse. It is during this time that Sage-Grouse perform courtship and select mates, prepare for nesting, nest and raise chicks. Breeding habitats are roughly centered on leks. Leks are where males compete for mating opportunities by performing strutting displays and producing complex vocalizations. Trees or other tall structures are generally not within line of sight of leks and are uncommon within two miles (Connelly et al. 2000; Stiver et al. 2010). After mating, females retreat from leks and seek out nest sites. Average distance from leks to nest sites varies among populations. Reported averages range from 0.7 to 3.6 miles, but this distance may exceed 12 miles. Cadwell et al. (1998) reported that female grouse in the YTC population nested an average of three miles from their capture lek. Early brood-rearing habitats occur close to nests but movements may exceed 1.9 miles as Sage-Grouse move to areas that have an abundance and diversity of herbaceous plants and insects, but may have lower sagebrush cover. Breeding/early brood-rearing season generally occurs from March 1 to June 30 (Stiver et al. 2010). Summer/Late Brood Rearing Habitat Late brood-rearing occurs during approximately July 1 to September 30 (Connelly et al. 2000; Stiver et al. 2010). During summer, as chicks grow and vegetation dries out, Sage-Grouse may shift habitats. These late brood-rearing habitats tend to be more mesic, forb-rich sites and may be dominated by sagebrush but may also include wet meadows, farm fields, and irrigated areas adjacent to sagebrush habitats (Connelly et al. 2000). Within the YTC population, females, on average, spend the summer and fall approximately four miles from the lek, while males average seven to eight miles away from the lek during summer (Cadwell et al. 1998). By fall, a slow shift toward winter range begins. Sage-Grouse continue to supplement their diet with remaining succulent forbs, but, by early winter, a transition to a sagebrush- dominant diet resumes. Winter Habitat Winter habitats are reached by December. Wintering habitat is typically similar throughout the species range and contains tall sagebrush or windswept areas with shallow snow accumulations. Sage-Grouse feed exclusively on sagebrush during winter. Big sagebrush is dominant, but Sage-Grouse will feed on a variety of other sagebrush species, depending on availability (Connelly et al. 2000). Habitat Assessments A Sage-Grouse habitat assessment was conducted in the proposed right-of-way (ROW) of Alternatives A- G in 2011. On public lands, field surveys were conducted using protocol based on BLM’s framework for assessing sensitive species habitats (Stiver et al. 2010). On private lands not visited, surveys were conducted through aerial interpretation using adjacent survey information, 2001 JBLM YTC vegetation data, GAP data, and fire history data. A Sage-Grouse habitat assessment for the NNR Alternative