[A mountain bluebird flies in the wind. Although it flaps its wings, it does not move forward. It seems to remain in the same spot. It then drops down and lands in the grass. It takes off again, once more appearing to hover in one place while flapping its wings.]End of transcript
Birds stay in the air by creating lift, which is generated when air passes over their wings, creating greater pressure below the wing than above it. This Mountain Bluebird is taking advantage of a specific type of pressure called dynamic pressure, which is created by moving air rather than by the bird’s wingbeats. It’s the same kind of pressure you feel when you’re struck by a strong gust of wind.
Recorded by Eric Liner