"Winged Migration" features some of the best tracking shots I've seen. Most of the film is just birds flying, and it is mesmerizing. It definitely shows how humans affect the birds' odds in the birds' travels, and Perrin has a heavy hand when he doesn't let the birds just carry the film.
Sparsely narrated and more visual than informative, so not as much of a nature documentary as I had anticipated. Also a tad deceptive, as there is CGI used a few times (contrary to the notice before the film) and the primary bird subjects had been raised by the filmmakers to ensure they would be cooperative with them. Still, spellbindingly beautiful to watch when humans aren't showing up and doing awful things.