Zack Snyder’s expensive movie Legend of the Guardians: The Owls of Ga’Hoole opened in theaters this weekend to a less-than-expected debut of just $16.3 million, Box Office Mojo is reporting. Tracking was indicating that the animated adventure might earn upwards of $20 million. Various reasons are being speculated for the film’s numbers, including mixed reviews from critics and an uneven marketing campaign from Warner Bros. Without anything else coming out for families in the next few weeks, however, it is possible that the movie could see some legs, especially since it has many 3-D and IMAX screens to itself at the moment.