The greater sage-grouse inhabit the “high desert” regions of the Rocky Mountains in the United States. Their behavior becomes quite unique during the breeding season. Males advertise themselves by inflating and deflating the air sacs on their chests, creating popping sounds. Only the strongest male out of one hundred competitors can win female mates and leave offspring. On the other hand, chicks of the greater sage-grouse face considerable danger because they easily become targets for birds of prey. The program shows the harsh battle for survival of these rare birds.