14: 1966-2013. Region L 95% CI U 95% CI N California -2.95* -4.10 -1.81 146 Colorado -0.62 -1.92 0.62 69 Idaho — — — — Oregon 1.52 -0.33 3.33 32 Montana — — — — Nevada -0.62 -1.97 0.73 39 Utah -0.73 -2.43 0.92 63 Washington — — — — Wyoming -0.73 -2.05 0.59 90 Northern Rockies — — — — Southern Rockies/Colorado Plateau -1.03 -2.37 0.30 91 Basin -0.69 -1.64 0.27 148 Badlands and Prairie -1.81* -2.72 -0.94 90 Shortgrass Prairie -2.53* -3.49 -1.62 113 Western BBS -1.76* -2.39 -1.16 536 Continental -3.20* -3.49 -2.91 2050 * Statistically significant (credible interval does not span zero). Values are not presented because of insufficient data. — Many studies found that fire negatively impacted shrike habitat, though the species most likely has a mixed response depending on fire characteristics and other environmental factors. In many states, the BLM has adopted a fire suppression policy, which many land managers believe will improve shrike habitat (Pruitt 2000). Studies by Welch (2002), Humple and Holmes (2006), and Holmes and Robinson (2013) all found that fire in sagebrush habitats reduced nesting and bird density; however, low intensity, patch burns could also benefit the bird (Poole 1992). On the whole, grazing also tended to negatively impact shrike habitat, but the effect will vary by practice and location. Page et al. (1978) found no impact from grazing in low sagebrush; results were inconclusive in big sagebrush. In a low-shrub desert, Medin (1986) found no significant difference between ungrazed plots and heavy, late winter grazing plots; shrikes were infrequently observed at the heavy, early and middle winter grazing plots. Prescott and Collister (1993) found that Loggerhead Shrikes preferred undisturbed areas, but the study was not in
14: 1966-2013. Region L 95% CI U 95% CI N California -2.95* -4.10 -1.81 146 Colorado -0.62 -1.92 0.62 69 Idaho — — — — Oregon 1.52 -0.33 3.33 32 Montana — — — — Nevada -0.62 -1.97 0.73 39 Utah -0.73 -2.43 0.92 63 Washington — — — — Wyoming -0.73 -2.05 0.59 90 Northern Rockies — — — — Southern Rockies/Colorado Plateau -1.03 -2.37 0.30 91 Basin -0.69 -1.64 0.27 148 Badlands and Prairie -1.81* -2.72 -0.94 90 Shortgrass Prairie -2.53* -3.49 -1.62 113 Western BBS -1.76* -2.39 -1.16 536 Continental -3.20* -3.49 -2.91 2050 * Statistically significant (credible interval does not span zero). — Values are not presented because of insufficient data. Many studies found that fire negatively impacted shrike habitat, though the species most likely has a mixed response depending on fire characteristics and other environmental factors. In many states, the BLM has adopted a fire suppression policy, which many land managers believe will improve shrike habitat (Pruitt 2000). Studies by Welch (2002), Humple and Holmes (2006), and Holmes and Robinson (2013) all found that fire in sagebrush habitats reduced nesting and bird density; however, low intensity, patch burns could also benefit the bird (Poole 1992). On the whole, grazing also tended to negatively impact shrike habitat, but the effect will vary by practice and location. Page et al. (1978) found no impact from grazing in low sagebrush; results were inconclusive in big sagebrush. In a low-shrub desert, Medin (1986) found no significant difference between ungrazed plots and heavy, late winter grazing plots; shrikes were infrequently observed at the heavy, early and middle winter grazing plots. Prescott and Collister (1993) found that Loggerhead Shrikes preferred undisturbed areas, but the study was not in
Sagebrush%20birds%20WAFWA%20draft%2010-27-16.docx