Step 1:In Chapter 1, near the sheep bridge where you unlock
Bunny Buddies &
Black Sheep, before crossing the bridge, make sure you head to the right of the crank on the balcony area and interact with the bird cage to set the bird free.
Step 2:During after the
windpipe achievement in Chapter 4 (near the inventor), head down towards the wind glider and use the telescope halfway down the stairs. From the starting position, aim down and to the right to find a bird sitting on a branch and then zoom in to unlock the achievement.
Note: If gaining this achievement through Chapter Select, complete the part in Chapter 1 and then continue to a checkpoint. Now back out to the main menu, and select Chapter 4 playing up until you unlock the achievement.
This achievement can be seen in the video guide at
3:19 &
7:06.