Males with large racks are generally the most successful in breeding. The sight of a large rack is not lost on lesser males either. Often, simple posturing and displaying an impressive rack is enough for an elk to deter a fight. When fighting does occur, however, elk can wield their antlers like unsheathed swords, poking out eyes and slicing skin. During the heat of the rut, it's not uncommon to see elk or deer with snapped-off antlers.
Many older bulls bear the scars won during years of epic battles.
By the onset of winter, the rutting season wanes and so does the testosterone level in males. They're tired from the rut and need to shed the extra weight to avoid susceptibility to predators. A loss of calcium around the base of the antlers weakens the connection, and eventually the antlers drop off. Shedding takes place between late November and March for males. Female caribou don't cast their antlers until after the calving season in June.