Awesome! I love the head and the anatomy! The only thing I'd have to critique is the layering of the feathers. When looked on from above, the last feather on the wing would have to be under the other ones, and you drew practically the view from below (would be really hard to fly with wings attached the wrong way )
I think the wings have been removed just so they don't get in the way of showing the viewer what the saddle looks like. Alot of conceptual artists will do this with various layers of a piece of their work. It just makes things easier for the viewer and makes the design clearer by removing a bit of anatomy .