"For the first time in months, a buck's velvet is gone and his testosterone levels are rising. If he's got an attitude, he's now got hard antlers to go with it. Put him next to another belligerent buck, and there's going to be a brawl," Marum explains. "Also, as summer bachelor groups break up, bucks begin establishing home core areas for the fall. As they disperse, they bump into competing strangers--and sometimes they duke it out."