As a sea fog shrouds this island, these walruses sense they are in danger. Faced with an imposing wall of blubber and hide, has this polar bear met his match? Celebrate 20 years of Planet Earth. Head over to the webpage to find out more: https://www.bbcearth.com/shows/planet-earth #PlanetEarth #DavidAttenborough #PE20 Subscribe: http://bit.ly/BBCEarthSub Sign up to our newsletter for the latest news, updates and exclusives from BBC Earth https://www.bbcearth.com/newsletter 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 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