Some of the photos in this post are taken by my lovely assistant Stevan, and are therefore blurry and terrible, but well-intentioned!
Make and attach the tail in the same fashion as the wings; first I made a flat shape of the darkest color, then poked feather-shaped layers of different colors on top of it. Once it was constructed, I poked it onto the kea's body, adding a bit more of the dark-colored wool to the underside to better blend it.