Birds, elephants, and lions will be battling one another at the box office this weekend, and when the dust settles, the winner will be ... Madea. That's the conclusion of most industry forecasters, who note that Tyler Perry's character has been drawing ever bigger audiences -- the last Madea movie, Madea Goes to Jail, opened with $41 million in 2009 -- since Perry introduced her in 2005. They're estimating that Madea's Big Happy Family will earn $30-35 million this weekend. (Like Perry's other films, it was not screened in advance for critics.) The film's strongest competitor, they indicate, will No Doubt be the 3D animated Rio, which opened ahead of forecasts last weekend and has been raking in solid returns during midweek, what with many children still out of school for spring break. Coming in third, they forecast, will be Water for Elephants , starring Robert Pattinson and Reese Witherspoon, based on the best-selling novel by Sara Gruen. Fans of the book and fans of Pattinson, the Twilight star, should boost ticket sales to around $15-20 million, according to the forecasts. The Disneynature documentary African Cats also makes its debut this weekend, but it's not expected to roar. The last Disneynature film, Oceans, opened last year with just $6 million.