The correct answer: Sparring
The rut begins in late August after cow moose have spent the summer feeding, gaining weight, raising calves, and growing a new coat. At first, things progress slowly. Bulls with newly unsheathed antlers may lightly spar, but there is no attempt to injure each other. By mid-September, bulls start to compete for breeding rights to the groups of cows that have started congregating. They do this by fighting.