The 3D animated misadventure of a Brazilian macaw scored the biggest opening so far this year at the North American box office, and was the top choice overseas for a second weekend, distributor 20th Century Fox said on Sunday. The film sold an estimated $40 million worth of tickets across the United States and Canada during the three days beginning April 15, coming in at the top end of expectations. It also provided some rare good news at the box office where sales so far this year are down 19 percent to $2.65 billion, according to box office analysts at Hollywood.com. The previous best launch this year was the $38 million bow for the Johnny Depp cartoon “Rango,” which remains the biggest release of 2011 with $119 million. “Rio” ended the two-week reign of another cartoon, the Easter-themed “Hop.” Buoyed by strong critical reviews, an “A” rating among patrons polled by tracking firm CinemaScore and the spring break/Easter holiday, “Rio” should have little difficulty becoming the year’s first big blockbuster. Its foreign haul rose to $129 million after a $54 million weekend in 62 markets.