David Roberson <dlrober...@aol.com> wrote: Can you imagine a large flock of birds traveling through a windmill farm? > Avoiding two types of collisions at the same time might overpower their > abilities.
It doesn't seem to be a problem, as far as I know. They do try to avoid putting wind turbines on major migratory pathways. There was quite a to-do about this when wind energy first become popular. There were many studies. Wind turbines do kill ~500,000 birds and bats, but mainly from environmental fragmentation and power lines, not the turbines themselves. See: http://www.scientificamerican.com/article.cfm?id=wind-turbines-and-bird-conflicts As I said, birds are evolved to avoid whacking into things like tree branches moving in the wind. Flocks of birds do this too. Generally speaking, animals can do what they are evolved to do, but not something they never encounter in the wild. Birds whack into glass windows because there are no vertical mirrors in nature. People climb trees to shoot deer because North American deer do not have predators who attack from above, so they do not look up often. - Jed
