This article takes a fairly optimistic view of bird and bat killing by wind turbines, and attempts to put the rather large numbers into some kind of context. Even the windows in all of our homes kill some birds - where do you think the 2 or 3 inch diameter holes in the screening on your 2nd floor windows come from?
One interesting fact in the link above is that Norwiegan researchers have evidence that painting one of the three blades black reduces bird strikes almost 70%. An intersting aproach.
Here is another article from the US Fish and Wildlife Service which projects up to 1.4 million kills annually by wind turbines. What is not expressed is that some of the birds killed are bald eagles which are a protected species, and that injuring a bald eagle industrially might not be tolerated in many industries, unlike the more favored wind turbines....
The power lines from electrical plants - whether wind or natural gas or solar powered - are all potentially dangerous to wildlife as described in this link, below, to the American Bird Conservancy - this link may be more controversial, but does say it supports renewable wind sources despite their significant risks to wildlife
I do know that highly valued birds do sit in, on, and around those high tension lines, as I saw 4 juvenile eagles sitting on an electrical high tension tower locally - but two flew off before I could get my camera freee, so I only have two juvies in my image. below. Yes, the tower poles are wooden, but the lines are definitely high tension.