Feathers

When playing Angry Birds, Angry Birds Rio, Angry Birds Seasons, and Angry Birds Facebook, after successfully completing a level (killing all the pigs), a player may choose to play the level again to earn a feather. To this, players must first purchase the Mighty Eagle option for their particular platform. In the Angry Birds Seasons episode Year of the Dragon, the Mighty Eagle is replaced by the Mighty Dragon. The Mighty Dragon is free to use for all players using iOS, Android, and Symbian, even if they have not purchased the Mighty Eagle. Instead of earning feathers, the Mighty Dragon earns Red Koi Fish.

When one uses the Eagle or Dragon, they will perform their attacks and try to destroy all (or at least a majority) of the objects on the screen. After the attempt, a meter will show the level of destruction as a percentage. If 100%, or “Total Destruction” has been achieved, the player will earn a feather/koi.

Feather Display
The feather appears on the level selection screen. Each level will display the number of stars that it was completed with and if a feather was earned. Additionally, the Episode selection screen will display how many feathers were earned out of the total possible for that Episode. For the Mighty Dragon, the feathers were replaced by a red koi fish icon.

Achievements
Achievements for the Apple Game Center can be won for earning feathers:

Angry Birds:
 * Feather Picker: 50 feathers earned, 10 Points
 * Feather Collector: 100 feathers earned, 20 Points
 * Feather Gatherer: 200 feathers earned, 30 Points

Angry Birds Seasons and Rio:
 * Feather Picker: Earn 30 feathers, 10 Points
 * Feather Collector: Earn 60 feathers, 20 Points
 * Feather Gatherer: Earn 120 feathers, 30 Points