Finally, we are starting to get answers to that universal question: Who would win in a fight, cats or wind?

If the fight is "who can kill the most birds," the cats are way ahead, says a new study in the Journal of Ornithology. For sheer avian death tolls, wind turbines can't even hold a candle to the feline contingent — they kill 440,000 birds a year, to cats' 500 million. Even with expanded wind power over the next 20 years, turbines are only expected to kill a paltry million of our feathered friends. I've bumped off that many in a couple hours of Angry Birds.

When it comes to larger birds, though, turbines are still a problem. And larger birds include threatened species like whooping cranes and eagles, which have enough troubles without being sliced up by random mechanical fins in the air. So it's still important to be conscious about local ecosystems and biodiversity when putting up wind farms. But we should maybe also do something about those cats.