Nature documentaries have been around since the invention of film. Disney Studios has been making docs since 1948 when they started making nature shorts under the banner True-Life Adventures which started with Seal Island. They made several short docs up to 1953 when they made their first full-length feature documentary in the series The Living Desert. In 1954 they followed it up with The Vanishing Prairie These documentaries won Disney a lot of acclaim and awards. They also paved the way for more nature documentaries and a little bit of laziness.
In 1958 they made White Wilderness, a documentary that followed several animals as they try and survive in the Arctic. The problem with the doc is that some scenes were faked. Alberta, Canada was substituted for the Arctic and a scene where lemmings were supposedly migrating to their death was actually staged and the poor critters were really being pushed into the Bow River near downtown Calgary. Another scene involving a polar bear cub falling down was shot in the Calgary Zoo. Classy.
Disney stopped the True-Life Adventure series in 1960 after having made 16 films but they have recently began making new docs under the Disneynature banner.