Catching a bird in flight can be a tricky thing. When I’m sitting or walking along the beach, I’ll have my camera settings at whatever is appropriate for the subject matter and lighting, but when I’m between deliberate shooting, I will change my camera settings so that I am ready for fast shooting, just in case a bird of some sort flies by. I like to shoot at f8 to get wings as well as a bird’s body in focus, and if that means shooting at a higher ISO, then so be it. Changing settings as you are tracking is distracting when also trying to compose a shot, not to mention, adding to an additional hit and miss aspect of capturing the image.