So a few weeks back I demoed a folding wing ring based on Jared Reisweber's notes. It didn't look much like a crow though - it was more of a soaring wing type. I spent most of today pushing verts around and working with shape keys to get the fold even better and solve the distortion problems at the extreme poses. I'm using a solidify modifier post-armature on the feathers to take give them some thickness - I had to separate them out from the rest of the mesh after binding. Most of the above bones will be hidden at animation time leaving 4 main controls per wing and 8 tweaks for follow through and puffing out etc. Not sure what I'm going to run with for simming yet - maybe just animated displacements.