Living with wind energy

Bats and turbines can share the sky.

Hoary and silver-haired bats spend the warm months here, arriving in spring and raising their young through summer before heading south for winter. They are also the two species most often lost at wind farms in North America, with deaths peaking during fall migration. These are long-lived animals that raise just one litter a year, so even small yearly losses add up faster than the population can replace them.

The encouraging part is that most of these losses are preventable. The majority happen on calm, low-wind nights during late summer and fall migration, exactly when turbines generate the least power. Slowing or feathering the blades until the wind picks up on those nights, a practice called curtailment, has been shown to cut bat fatalities by half or more.

That is part of why these images are free. The more people who know these animals exist, the more who will want to keep them in our night skies for generations to come.