Why does a bird fly, but not flap its wings?
Why is the bird flying with its wings down in this video shot on a home security camera? Because the frame rate of the camera coincided with the wingspan frequency. Each time the camera moves from shooting one frame to the next, the wing manages to go the same distance and be at the same point at which it was, the previous frame was shot. Previously, we observed how this overlapping of frequencies works for the rotating blades of a helicopter (it seems that the helicopter flies with the rotor off), but now it’s the turn of birds. It can be seen that in this case the frequency of the swings coincides with the frame rate only when the bird is directly in front of the camera; a little to the side - and the video shows how the bird spreads its wings.
Floaty bird floating