They multiply in to three! AND they sound like they're saying ha-hooey ha-hooeyThey also say ROGER before launch
The Blue Birds (also known as the Triple Threat Bird, Cyan Bird, Multiplier Bird, Light Blue Bird, Splitter Bird, Glassjaw Bird, Blue Ice Bird, Trio Bird, Shotgun Bird, Cluster Bird, or Glass Breaker...
You don't get the last bird.
it completes a level