Leeneia, the bird identification sites I've found sometimes refer to this bird as a red-shafted flicker woodpecker (or a yellow-shafted one, but they're supposed to be eastern) and sometimes just as a red-shafted (or yellow-shafted) flicker.    Is there a definite difference between a flicker and a woodpecker, or are flickers a sub-category of woodpeckers?