There's a lot of pheasants around here, they're raised in captivity and then released for shooting, I've had loads of near misses with them flying out in front of me (sometimes at 40+mph)is the gamekeeper responsible for them? where would you draw the line?
A rabbit runs out of a farm gate, its OK, a chicken, its not?
I think the only safe answer is; ride at such a speed that allows you to safely avoid collisions.
If you want to ride faster, be prepared to pay the price.