Howdy Y'all
You people are doing some fine work - Two things, Have you ever heard of a human ailment called Vertigo? I believe it is a snag with the inner ear which causes a loss of balance. Could birds have a similar but more developed system to act as a gyro.
The second thing is nothing to do with birds, I have heard a number of learned persons say that Bumble Bees wings are not large enough or fast enough to create lift in excess of their weight. Yet they fly I know, I've seen them. Any thoughts?