Here's kind of a cool video. This was last June 1st. At about the 25 second mark you see the group leader asserting himself. Interestingly, his rack is far more developed than all the other bucks that I have on video around that time. The second video is also from June first (four bucks) and it's a couple rearing up at each other. You notice their antlers (like most in the first video) are just starting to come in.