Zoo animals are still in demand at North America's cinema box offices.
Ben Stiller and his voice co-stars of Madagascar 3: Europe's Most Wanted held on to the number one spot, with 35.5 million US dollars for the animated sequel's second weekend in domestic theatres.
Studio estimates put Ridley Scott's sci-fi adventure Prometheus second again with 20.2 million US dollars.
Madagascar 3 and Prometheus held off two under-achieving newcomers. The star-studded musical Rock of Ages, whose cast includes Tom Cruise, Catherine Zeta-Jones and Alec Baldwin, flopped at number three with 15.1 million US dollars.
Adam Sandler's That's My Boy bombed with 13 million US dollars, the worst showing for one of his broad comedies since the mid-1990s.
That's My Boy came in at number five, behind the 13.8 million US dollars for Snow White & the Huntsman, a film that's been out for three weekends already.
