With “Rio 2,” the creators of “Rio” give us more of everything that their first film had in just the right doses. But if this sequel proves anything, it’s that more is not always better.

There are more stars in this birds-of-the-Amazon musical, with Broadway’s Kristin Chenoweth, Oscar winner Rita Moreno and pop star Bruno Mars joining in. And all of them sing. Because there are more tunes.

There are more animals for those stars to play, including an exquisitely animated spotted tree frog
(Chenoweth)
. And there’s more story, as Jewel (Anne Hathaway) and Blu (Jesse Eisenberg) take their brood (they now have three kids) into the Amazon to help Linda (Leslie Mann) and her scientist-husband Tulio (Rodrigo Santoro) track down a rumored lost, last flock of bright-blue macaws of their species.

But one thing the overlong “Rio 2” lacks in extra supply is jokes. A script designed to give cute moments to everybody from the first film as well as all those brought in for the second is a cumbersome, humor-starved affair.