The following birds have actually the noted special capabilities.

Blues: Splits into 3 and travels through ice.
Bomb: Explodes upon demand after a tap or after he lands in a particular area.
Chuck: Moves in a straight line that can get rid of wooden pieces.
Matilda: Tap to drop an egg bomb. After laying the egg, Matilda will certainly get a flight boost.
Red: Can move strong stone blocks. Tap to have Red release a gust of energy that can break stone blocks.
Silver: Tap to start a loop that winds up downwards at the point where the loop began. She can get blocks throughout the loops, and can connect of place pigs concealing under blocks.
Terence: No special capability, however can that damage anything in his way.