While to a degree that's true, along with waylar's #10 sit down for a brew & smoke, if I'm openly working in the fields the wildlife takes absolutely no notice of me because I am no threat, but if I stop working & take my rifle off the rack, everything starts to get tense & heads for cover.
I'm certain wildlife can sense when a person or animal decides to become the hunter and starts to take interest in them, I've had foxes happily walk past 20yds away while I'm using a chainsaw in the woods because I'm not being a threat
But when you are hunting & they sense it then you do need to be 100%