district attorney george gascon, brandon martin ppic, david greenburg, chief deputy district attorney in san diego. >> you're welcome. >>> if you've ever driven through the alta mont pass near livermore you've noticed thousands of turbines in the area. those turbines generate energy from the wind but they also pose a threat to the thousands of birds that fly through the alta mont. hundreds of birds of prey die in collisions with turbines every year. this week one of the largest wind farm operators at the alta mont says it's shutting down all its turbines. the company want toth replace them with more efficient turbines. kqed science reports biologists say such steps are needed to protect threatened species. >> reporter: the alta mont pass east of san francisco is home to hundreds of bird species. they hunt and play in the midst of 3,000 wind turbines. those turbines can be deadly, especially to golden eagles. >> there's an eagle right there. >> eagle, eagle! >> below the horizon -- >> reporter: biologist doug bell, sean smallwood, and joe diganado study golden eagles. >> it's got white