I'm with Nigel on this.
I have done a fair proportion of my flying in "turkey buzzard" country. They usually fold everything and dive-even if they are above you. When you are slowed below 200kts there is often a chance to make some (token?) evasive action, but above that speed by the time you see them, even if you react immediately, the inertia of the aircraft and "radius of turn effect" means that the effective trajectory of the aircraft is little changed.
Anything smaller than a buzzard is usually an "oh !!!!! what was that??!" event.
My company had a landing lights on below FL100 "be seen" policy with mainly birds as the objective.