In my experience flying, when you have one that is in your vision it's usually too late to make drastic changes. Birds in our area tend to dive when we are approaching them, if you see a bird above you it makes me very nervous. It never stops surprising me how little I seem to be able to do when I do see a bird, maybe a small nudge on the yoke. Also short final or just after rotation on takeoff seems to be where i've had most of my near-misses with them.