A Great Egret in flight makes hardly a sound. They can be surprising fast, but usually they push slowly with their powerful wings. During any given day probably 1/2 the Egrets we see are missed opportunities because we didn’t hear them in time.
Catching a good photograph of a flight has the usual problems of getting focus and speed. However because they are such a large bird the focus ‘spot’ is critical also. Mid body or shoulder is best for me. If not either the front or back of the bird is out of focus. They are that big during a close up photo.
I prefer to be a little further away than these shots just for that reason. This was a 10 shot series, maybe 3 were decent focus.