I came across great stock images of birds by this guy a while ago and I've been wanting to do a study of some wings ever since. I added a fancy background and some text to make it look more like a real picture and less like a half assed speedy.
EDIT : Yoult on deviant art pointed out very accurately that pigeons do not possess true tertials. True tertials attach to the humerus while secondaries attach to the ulna. In pigeons, it is not the case and while the term is apparently used to refer to some specialised secondaries in some species and songbirds, it is not really accurate. I have therefore removed the 'tertials' tag.