I checked this bird rigging reel a little while back and find these setups to be really intuitive and pretty straight forward; flexible controls producing proper articulation by Rebecca Lórien. You can see that the rigger has used a blend of fanning joints placed in anatomically correct position and spline based control/deformation, somewhat similar to or look alike Paule Neale’s Setup for the wing and feather system to achieve believable wing spreading, folding and flapping articulation.