I had been rather amazed by Winged Migration when I watched it. Then I watched the "making of" featurette on the DVD, and all I can say is, that's crazy!

They actually raised a number of different bird flocks from the egg: gees, cranes, swans, pelicans, etc. and had them imprint on human so as to be able to fly with and film the birds up close and personal. That's some serious commitment. Cool and yet mildly disturbing at the same time.

I do wonder what became of the birds after all the filmmaking was finished.