Male giraffes use their necks as weapons in combat, a behavior known as "necking". Necking is used to establish dominance and males that win necking bouts have greater reproductive success.The contestants will try to dodge each other's blows and then get ready to counter. The power of a blow depends on the weight of the skull and the arc of the swing. A necking duel can last more than half an hour, depending on how well matched the combatants are. Although most fights do not lead to serious injury, there have been records of broken jaws, broken necks, and even deaths.