To reach new feeding grounds, this family of proboscis monkeys must cross a crocodile-filled river Subscribe: bit.ly/BBCEarthSub Watch more: Planet Earth bit.ly/PlanetEarthPlaylist Blue Planet bit.ly/BluePlanetPlaylist Planet Earth II bit.ly/PlanetEarthIIPlaylist Planet Dinosaur bit.ly/PlanetDinoPlaylist Taken from Earth's Tropical Islands episode 2 'Borneo' Three iconic islands. Madagascar. Borneo. Hawaii. Each a contained ecosystem, cut off from the mainland. Rich in extraordinary wildlife and human cultures, these islands are also some of the most fragile places on Earth. 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. Want to share your views with the team? Join our BBC Studios Voice: www.bbcstudiosvoice.com/register This is a page from BBC Studios who help fund new BBC programmes. Service information and feedback: bbcworldwide.com/vod-feedback--contact-details.aspx