Caged Birds

Caged Birds are a few species of birds (purple, pink, red, blue, yellow and green; also a Blue and Gold Macaw and a Scarlet Ibis) that appear in Smugglers' Den, Airfield Chase and Smugglers' Plane as prisoners of the Smugglers. It is implied that they, like the Angry Birds (Red, Jay, Jake, and Jim, Chuck, Bubbles, Hal, Matilda, Bomb and Terence) are rare species as the official game trailer refers to them as "exceptionally rare species". The other birds try to free them from their cages by slinging themselves at the cages; when a cage breaks, the caged bird flies away. Upon level failing, they will start crying for help which leads to the player failing the level.

Trivia

 * The designs of the Crimson-hooded Manakin and Purple Finches would later be reused for the chicken designs in the Angry Birds Friends Kentucky Free Chicken Tournament.
 * The Scarlet Iblis in Carnival Upheaval's cutscene is dark green instead of red.