Shoot it vertical and practice!
Here is a Crested Auklet from my recent Saint Paul Island Workshop. If you want to improve your birds in flight skills, try shooting with your camera turned vertically to Portrait mode. As I age, my vision, reflexes and hand-eye coordination are all working hard to slow me down - I stay sharp by spending hours tracking super small, fast and erratic birds in flight and often orient the camera vertically - smile.