It's the most important moment of the year for these male bighorn sheep – each female is fertile for just two days. But first, the rams must do battle to decide who gets to mate. Subscribe: http://bit.ly/BBCEarthSub #BighornSheep #AnimalBattle #RockyMountains Watch more: Best of BBC Earth 🌍 https://bit.ly/BestOfBBCEarth Best Animal Fights 🥊 https://bit.ly/BestAnimalFights Videos over 10 minutes ⏰ https://bit.ly/3SHJCEJ Planet Earth III 🌍 https://bit.ly/PlanetEarthIIIPlaylist Frozen Planet II ❄️ https:/bit.ly/FrozenPlanetIIPlaylist Blue Planet II in 4k 🌊 https://bit.ly/BluePlanetII4kPlaylist Taken from 'Mountains: Life Above The Clouds' (2017) Mountain ranges cover 25 percent of our planet. 40 percent of the world's population depend upon them to survive. Yet to most of us they are a secret hidden realm. We will take you on an awe-inspiring journey to the four most iconic mountain ranges on the planet with a narrative arc taking us from the foothills up to the soaring peaks. Welcome to BBC EARTH! The world is an amazing place full of stories, beauty and natural wonder. Here you'll find 50 years worth of entertaining and thought-provoking natural history content. Dramatic, rare, and exclusive, nature doesn't get more exciting than this. This is a commercial page from BBC Studios. Service information and feedback: http://bbcworldwide.com/vod-feedback--contact-details.aspx