earth

... I don't know. What?

Here's the thing, in 2006 BBC teamed up with Discovery Channel and produced an 11 episode miniseries called, interestingly enough, Planet Earth. Seeing as how they used around 8 hours of gorgeous footage, I imagine there wasn't much left for when DisneyNature called them up.

Not only was the footage exactly the same, but I'm pretty certain that much of the naration is similar, if not exactly the same as BBC production. The main difference is that when displaying the more violent aspects of the circle of life, the BBC had no problem showing animals eating other animals. In the Disney version, the chase ensues the predator catches it's prey, and then the editor switches to another beautiful vista.

If you liked March of the Penguins and you have not seen the BBC/Discovery miniseries Planet Earth, the by all means, see Earth. I would, however, recommend Planet Earth over Earth. It's available on Blu-ray and it's segmented so you can pick and choose what areas you want to see. I suggest the Deep Ocean and Caves episodes (which weren't covered in Disney's version.)