While many see wind power as a renewable source of earth- friendly energy, increasing numbers of conservationists are taking a dimmer view of them because of their impact on wildlife – particularly bats. According to a new study at the University of Colorado, some 600,000 bats were killed by wind farms last year – and some of them were endangered varieties. This grim figure comes from data taken at some 21 wind farms studied nationally, but may well understate the actual death count by 50%. Since many of the bats are killed not just from the spinning blades, but also by air turbulence created from the turbines, it seems wind power may be spinning itself into some real trouble with wildlife officials.