This from Wikepedia.....The movie was shot over the course of four years on all seven continents. Shot using in-flight cameras, most of the footage is aerial, and the viewer appears to be flying alongside birds of successive species, especially Canada Geese. They traverse every kind of weather and landscape, covering vast distances in a flight for survival. The filmmakers exposed over 590 miles of film to create an 89-minute piece. In one case, two months of filming in one location was edited down to less than one minute in the final film.
Much of the aerial footage was taken of "tame" birds. The filmmakers raised birds of several species, including storks and pelicans, from birth. The newborn birds imprinted on staff members, and were trained to fly along with the film crews. The birds were also exposed to the film equipment over the course of their lives to ensure that the birds would react the way the filmmakers want. Several of these species had never been imprinted before. Film was shot from ultralights,para gliders, and hot air balloons, as well as trucks, motorcycles and boats. remote-controlled robots, and a French Navy warship. Its producer says that "Winged Migration" is neither a documentary nor fiction, but rather a "natural tale".
The film states that no special effects were used in the filming of the birds.
I wish that I had researched this more before we watched it. Joe kept saying, "How do they get such shots?" We didn't know about them raising some of these birds and the imprinting that took place. To me...that would have made it all the more interesting. So, if you're looking for some entertainment on a hot afternoon this summer, watch this film...you won't be disappointed. You can rent it from Netflix or maybe your local library can get it for you.