I hope you don't think I'm cruel because I'm not, I love all animals, but I run a hunt test here in Oregon. It's training gun dogs how to point, set and retrieve a bird. In a nut shell we basically do the same thing but we spin the birds gently and "plant" them in tall grass clumps in an open field, this kind of makes them dizzy so they just sit very still until the dog points them and the handler "flushes" them out by lifting them quickly with their foot, that abruptly brings them back to reality, then they fly. Birds seem to get dizzy very easily and they just hunker down. We use Chukar but I would think this would apply to most birds.
Just a guess as to why the chicken is holding so still.
By the way, we don't shoot the vast majority of the birds, only for the master and senior levels, most of our dogs are still trying to earn their junior hunting titles so the birds get to go free, which is far better then a life of captivity in a tiny cage.
