The operators of large California wind farms are considering the use of advanced radar and telemetry systems to reduce the number of birds killed by spinning turbines located in critical migration pathways. The so-called avian radar systems, which 
have been deployed at wind farms in Texas and Europe, would be able to identify birds early enough to shut down the turbines, at least briefly, to prevent collisions. Advocates say the systems could prevent large-scale killings of many migratory songbird species, as well as the critically endangered California condor and the federally protected golden eagle. According to the Los Angeles Times, one possible customer for the radar systems is the Los Angeles Department of Water and Power, which operates a wind farm that is under federal investigation following the discovery of several dead golden eagles at the site. “Renewable energy operators are coming around to the view that they have to do something,” said Gary Andrews, chief executive of De Tect Inc., a manufacturer of such systems. The systems, however, are expensive, at $500,000 per unit, and existing technologies typically have difficulty differentiating among bird species.
American Bird Conservancy