Happy Birthday to David Attenborough. The legendary naturalist turns 100 today. Few people have done more to educate the world about wildlife and conservation. Since the 1950s, Sir David has been presenting and narrating wildlife documentaries in his calm and reassuring voice. The camera crews who have worked with him have captured some of the most compelling and awe-inspiring footage ever recorded of planet Earth. As a tribute, PetaPixel has rounded up some of the best David Attenborough moments on YouTube. Gorilla Encounter The program and moment that started it all. During the filming of Life on Earth in 1978, Attenborough somehow ingratiated himself with a family of mountain gorillas in Rwanda. The analog age meant that the film crew was hesitant to start filming until Attenborough started talking about how dexterous gorillas are.…