While photographing a herd of Bison which also included some young baby bison , I was confronted by this sentry bison.. Bison have some of the traits one finds with elephants as far as how they interact and protect the overall family unit of the herd. These sentry bison act as interference or guards in that they will put themselves in between a perceived threat and the babies or herd in general. Such is the case with this bison.The herd was grazing, I and a few others where attempting to photograph them and this one bison looked up and saw us and proceeded to walk over and place himself in between us. He pretty much kept this stare down pose at me until I had finished and started to walk away . Then he walked away and went back over to where he first was in the first place. It was rather facinating to watch the dynamics of how the herd family interacted and protected itself..