I think birds might just be better adapted to making highspeed course corrections than deer, squirrels, etc. Plus, they have the advantage of another dimension

I think birds might just be better adapted to making highspeed course corrections than deer, squirrels, etc. Plus, they have the advantage of another dimension (and gravity) to use for getting out of the way. Consider also that if a deer is spooked and freezes on the highway, you hit it. If a bird is spooked and freezes in mid-air, it falls to the ground.