Wilson’s team tied audio recorders to drones with a fishing line 8 meters long to eavesdrop on birds. The lines were long enough that the microphones wouldn’t pick up noise from the drones themselves. The set up also allowed drones to hover at a reasonable distance from the birds they set out to observe. Rather than flying for miles, the drones hovered to act like a human ornithologist conducting what’s called a point count. In a point count, an observer jots down a note about all the birds they can see and hear from a certain location for a set period of time.