1 Oil and Gas Development in Western North America: Effects on Sagebrush Steppe Avifauna with Particular Emphasis on Sage-grouse

Sagebrush (Artemisia spp.) steppe was once a dominant feature of the landscape in western North America covering at least 243 million acres (60 million ha) (Beetle 1960, Vale 1975) in 16 states and 3 provinces. Most of this vast expanse has been altered by human activity. Estimates of complete loss of sagebrush-dominated areas exceed 50 % (Schneegas 1967, Braun et al. 1976, Braun 1998). The remaining sagebrush steppe has been markedly altered through treatments to benefit livestock grazing including livestock grazing as a treatment, fragmentation (roads, power lines and other structures, pipelines, reservoirs, fences, etc.), and degradation (Braun 1998). More recently, urban expansion as well as development of housing scattered through large tracts has impacted wildlife use of sagebrush habitats (Braun 1998)