The San Gorgonio wind plant consists of approximately 3,000 turbines of various types and sizes. Previous studies conducted at the San Gorgonio wind plant documented relatively low raptor fatality, with relatively higher fatality of passerines and waterbirds. Researchers estimated 6,800 birds were killed annually at the San Gorgonio wind facility based on 38 dead birds found while monitoring nocturnal migrants (McCrary et al. 1986). The 38 avian fatalities included 15 passerine species. McCrary et al. (1983, 1984) estimated that 69 million birds pass through the Coachella Valley annually during migration; 32 million in the spring and 37 million in the fall. Considering the high number of passerines migrating through the area relative to the number of passerine fatalities, the authors concluded that this level of fatality was biologically insignificant (McCrary et al. 1986).
The level of concern will likely remain high until we have a better understanding of the factors related to bird fatality. Studies, such as this research conducted in the San Gorgonio WRA, should provide valuable information regarding avian use and fatality and help reduce the level of uncertainty for wind energy development.