I don't get it. How can these birds know they need to fly up and rest on a rod? Well instinct is strong and the plain and simple reason is... most predators come from the ground... snakes, skunks, bobcats, small transformers - although I think they could fly in like a chicken, roost with them and then take shape into any predator. Can you imagine this...? The chickens sitting there... "Ahhhhhh cluck, cluck...." Here comes another chicken-looking chicken... clucking robotically and WHAM! It takes the shape of a toaster!
I have really digressed here.