The very large windfarm at Altamont Pass, California, kills over 4,000 birds, including more than 1,000 raptors, each year. In spite of numerous plans to remedy the situation since operations started over 20 years ago, nothing has worked to any signifiant degree.
The wind industry, and the bird societies* that support it, claim against all evidence that it is an exception. In fact, it is the rule, but very few windfarms are being monitored for bird mortality; and when they are, the media are not informed of the results.
*An exception is the Center for Biological Diversity, which has resorted to suing the Administration for the wildlife crimes perpetrated by windfarms, among other things.
*Another is Spanish Birdlife (SEO), which earlier this year decided to defend the birds, not the turbines. Prior to that they had been a vocal and efficient supporter of wind turbines, falsely negating their negative effects on birds.