Red Bird
This is the bird you start with, he does not have any special ability when you tap the screen. He is effective at breaking down the softer materials the structues are made of such as wood or glass.
Blue Bird
When you reach Level 10 of the 1st world you will come across this bird. When this bird has been launched you can tap the screen to make it split into three separate little birds. Tapping the screen straight after catapulting him will result in a far wider reach when they hit the structure whereas if you tap the screen just before hitting the structure you will cause more damage.
Yellow Bird
You meet this bird at Level 16 of the 1st world. When this bird has been lauched and you tap the screen it will dramatically speed up and therefore cause more damage when it hits the structure. These birds are particularly useful at reaching locations other birds are unable to get to and they are particularly effective against wooden structures.
Black Bird
At Level 5 of the 2nd world this bird will become unlocked. These birds are basically bombs, if you do not detonate them by tapping the screen they will explode anyway after a couple of seconds once landed. These birds are very good at taking out more solid structures.
White Bird
When you reach Level 14 of the 2nd world you will meet this bird who after catapulting will drop an egg bomb when you tap the screen. To deliver the egg bomb so it lands where you want it to requires careful aiming.
Boomerang Bird
At Level 5 of the 6th world you will meet this bird which when catapulted and you press thes screen will swing back at a faster speed like a boomerang. This bird can be tricky to use and will need some practice to become familiar with it. It is best saved for softer materials.
Big Brother Bird
You will meet this bird in Level 1 of world 9. It is a big bird capable of pummelling its way through most structures. This bird is basically a bigger more powerful version of the Red Bird and like his smaller version nothing will happen when you tap the screen.
Orange Bird
This bird will appear in the Ham'o'ween episode. When catapulted and you tap the screen it will blow up to several times his size when hitting something. Avoid inflating him too early as this will reduce the damage it causes. This bird is particularly effective when fired into a small gap in the structure while he is little and then expanded.
Mighty Eagle Bird
This bird can only be obtained by paying extra through an in-app purchase. He is the most powerful bird and destroys anything in its path. Once purchased it can be summoned once an hour by pressing the eye button which is accessed by pausing the game. If you use this bird to help you with a level you will not get any stars.