One of the hard shots that I get burned with is the ‘in and out’ flight. It’s usually the smaller wading birds that have this trick. In this case a Green Heron.
Basically the bird only wants to travel a short distance, fast. Their simple way is to drop down over the water quick, a few quick wing flaps along the edge, and back into the brush.
There is one particular swamp island this happens all day long. You know it’s going to happen, you wait, and …
You might catch a shot or three.