We get a lot of chickens crossing the road here on Kauai. I do know why they cross the bike path - so I don't hit them with my bike! They are actually quite good at gaging which direction to run when they see my bike coming, so I have faith they will scurry fully across before I get there. I used to slow down for them, but not anymore. They are a little smarter than I used to think!
I have heard it said, that most animals can judge how to avoid things which move up to about forty miles per hour. Perhaps because that is the maximum speed most animals, including most predators move. But animals really struggle to cope with speeds above forty mph.