In the first level of your quest, Red Tree Glade, after obtaining the ability to make a fire, burn your way through the cloth and continue. Eventually you come into a run in with a few crows. Decimate their numbers and proceed to the cliff side (the same one as where you start as Courage) where you will have another run in with a larger group of crows. Take them out and stand at the edge, go into first person mode, and Imitate the eagle to get this feather.
This achievement is required to progress through the story.