Global deforestation has been slowing down in recent years. But the encouraging news doesn’t tell the full story. Illegal logging is on the rise, hard to control and impossible to measure. Until now, that is. Drones are about to become the eyes in the sky of forest guardians in the Peru’s Amazon, just like they’re already spying on poaching activities from British Columbia to the Congo. Conservation is emerging as drones’ killer app, and there’s no stopping that trend.