text: Male elk bugling during the fall rut. Large male elk are known as bulls. Male elk have large antlers which are shed each year. Male elk engage in competitive mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which is intended to establish dominance over other males and attract females. Madison River, Yellowstone National Park, Wyoming, USA, Cervus canadensis, natural history stock photograph, photo id 19766