Focusing in on this Great Egret I saw the ‘bent’ knee sign of a quick takeoff. All birds have some type of signal, movement, they do to prepare for taking flight.
If you catch the sign at the right moment you have just enough time to get the distance right. I usually pull back my focal length to be sure the bird fits in the view finder.
This is the full sequence of the bird taking flight in front of me.
Click, or double tap, and image to view the gallery.