American Bird Conservancy:
"How many birds are killed by wind farms each year?
No one knows for sure. Recent estimates of the number of birds killed by wind turbines ranges from a low of 100,000 birds/year to 440,000 birds/year (calculated by the U.S. Fish and Wildlife Service). If 20% of the nation’s electricity comes from wind power by 2030, ABC estimates that at least one million birds per year will be killed by wind turbines, probably significantly more."
( http://www.abcbirds.org/abcprograms/policy/collisions/wind_faq.html )
PolitiFact/2010 - National Research Council / ABC: "The latest independent reports estimate the number of birds killed by wind turbines at about 100,000 per year. That’s according to a 2007 report from the National Research Council called “Environmental Impacts of Wind-Energy Projects.”
The American Bird Conservancy estimated in 2003 that between 10,000 and 40,000 birds were killed each year at wind farms across the country, about 80 percent of which were songbirds and 10 percent birds of prey.
“With the increased capacity over the last seven years, we now estimate that 100,000 – 300,000 birds are killed by wind turbines each year,” said Conservancy spokesman Robert Johns."
( http://www.politifact.com/truth-o-meter/article/2010/may/03/checking-george-will-birds-and-wind-turbines/ )
I’m guessing these are US numbers only.