“If the unprecedented box office success of documentary films in 2003 were itself the subject of a documentary, critics would find the plot wildly implausible and the explanations maddeningly inconclusive. A nearly wordless cinematic love poem to the flapping of birds, Winged Migration, has earned nearly twice as much money this year as that teetering blockbuster with Ben and J.Lo… Why this is happening to the much-maligned documentary category is much harder to pinpoint than box-office numbers. The most obvious answer: Good movies sell tickets.”