Birdman is a free flight mode where you can explore the islands with no time constraints or goals. By playing through the Extra Games, you can unlock the islands to explore by getting a silver metal or higher in the three classes of game. However, you can explore these islands temporarily by flying through special warp stars during Rocket Belt segments. Crashing into anything will end the game.
The warp star to this island's Birdman segment is placed under a rock arch to the east of where you start.
The warp star to this island's Birdman segment is placed at Central Park, New York.
The warp star to this island's Birdman segment is in a cave between two waterfalls, located on the northeast side of the main island.
The warp star to this island's Birdman segment is in a cave along the coast on the north side of the island.