There are both "Red-shafted" and "Yellow-shafted" Northern Flickers.
The "Yellow-shafted" males have the red crescent on the nape of the neck and black whiskers; the "red-shafted" males are not supposed to have the red crescent,
and have red whiskers. This male has both the red crescent and the red whiskers so not sure if he is hybrid of the two or what.