The perfect angle for one of the hardest in flight photographs.
Focus, or the lack of, is the issue here. These are big birds but all the large wading birds are nothing but feathers and bones.
Above I managed to get focus. You can see there is nothing to them. You can’t focus on something that you can’t see.
When they turn, still a very little bit, there is something to catch. It’s hard because of the fast motion but it’s there. This is what we need.
Also if you lose focus during the panning and motion shots a lens, no matter how good, has a hard time getting the focus back. This is where we all lose this sequence of photographs.
Since we have lots of practice with in flight shots it’s really up to the bird to give us something to work with. Without this (almost) exact angle we are not getting the shot.