Editorial

Bird mortality

Wind proponents regularly assert that bird mortality at wind energy sites averages at a low 2.3 birds per turbine per year. These collision figures were derived from outdated, and inadequate bird mortality studies conducted at land-based wind projects in western United States. William R. Evans, well-known ornithologist with expertise in nocturnal bird migration provided a critique of these studies in his 2004 testimony on the Chautauqua (NY) proposal ( http://www.windaction.org/documents/11726 ) where he states the Erickson, et.al. 2001 studies are "now widely seen as prematurely conceived."

Evans continues, "the high mortality figures associated with cats and windows predominantly involve plentiful species that are common in suburban and residential neighborhoods or in the vicinity of farms, whereas the species killed at commercial wind turbine facilities and communications towers are largely neotropical migrant songbirds; species of conservation concern that nest in our wild lands."

Recent bird mortality research from Europe ( http://www.windaction.org/documents/11725 ) found that collisions can vary substantially between sites with mortality as high as 103 to 309 birds/turbine/year. The researchers state that "[mortality] results of individual wind farms can not be generalized" but that "the collision mortality is mostly related to the number of (flying) birds present (at rotor height)". The Erickson et.al. numbers are inappropriately used by proponents to bolster their claims that pre-construction avian surveys are an unnecessary expense.

SEP 11 2007
http://www.windaction.org/posts/11087-bird-mortality
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