RE: Climbers?
It can be done quietly, although a guy told me once that bucks can be 'called in' by the climber. I'ver personally had numerous instances where a buck showed up while I was still climbing or had just gotten up the tree. Curiosity, maybe? Could just be coincidence (i.e. the number of trees I've climbed in the dark compared to the number of times the buck showed up while climbing or very shortly after).