© Marcel Burkhardt
Hardly any other bird is adapted better to life in the air than the Common Swift. This excellent aerial hunter resembles a swallow but flies at breakneck speed. It sleeps and mates on the wing. With Common Swifts wheeling higher and higher at dusk, it used to be thought that they returned when it was dark or spent the night on the moon. Emil Weitnauer, an ornithologist who lived near Basel, studied the night life of the Common Swift in detail, originally by balloon and aircraft, aided by strong headlights, later by radar.