I too have seen bucks and I mean wall hangers, tickling horns, sparring. I don't know if I attribute this to pre-rut as much as I do the bucks saying "Hey man,my Horns are hard now, lemme see if i can push you around"

It's kinda like the press conference before the fight..someones gonna talk trash and try to intimidate the other, so when the battle rages they have an edge.