It’s the weekend of Rio 2. Of bright colors and latin pop and Bruno Mars deciding he can act. And birds — big birds, small birds, bright birds, scheming Jermaine Clement birds. Rio 2 is the latest in a long tradition of bird-themed animated films; a tradition that dates back all the way to Disney’s early shorts like Chicken Little and The Ugly Duckling, and the feature-length The Three Caballeros. Then, sixty years of almost nothing. Once the digital age brought about a slew of new animated features, birds returned en masse. Our new heroes sported ruffled feathers and powerful wingspans. They also choked our cinemas to death with so many forgettable animated bird flicks. Surf’s Up, Happy Feet, Valiant, Free Birds and so forth. The future is dotted with more of the same with Storks, Angry Birds and The Penguins of Madagascar all planning to invade theaters in the next year or two. Now, this whole idea — that the “animated bird movie” is actually a thing, and a thing worth discussing, at that — may seem weirdly specific and potentially insane. It sort of is. But it works, and there’s actually a way to properly dissect a bird-centric cartoon. You quarter it into four distinct pieces; four categories that can be used to identify and analyze any animated bird flick. Categories that, when fulfilled, ensure the movie in question is a Chicken Run and not a Free Birds.