I personally favor moving the box around manually much more than some wildlife photographers, so I often stay away from the tracking modes.
In some autofocus modes, the camera can lock onto your initial subject and then track it around the frame. In others, you must manually move around the focus point as your subject moves. You’ll want to test out both approaches to see which one gives you quicker and more consistent results. I personally favor moving the box around manually much more than some wildlife photographers, so I often stay away from the tracking modes. But if you shoot very fast-moving subjects like birds in flight, you may find that autofocus tracking is a lifesaver.