The facial disc—the circle of feathers around each eye—acts as a pinna or dish antenna, directing sound to the owl’s colossal and complex ear openings, which are asymmetrical; the left ear opening is farther upward than the right. This asymmetry allows the owl to pinpoint the direction of a sound from its perch. And also, to locate prey in total darkness, as a barn owl does, with an error of less than one degree. The
