Northern, not Gilded Flicker
My apologies. I was misled by illustrations in the Smithsonian Birds of North America volume. The crown is partially shadowed in all three of the images (the two linked below and the one in the previous post) so is not helpful in identifying the bird, but the photos linked below clearly show the color of the tail and undersides of the wings to be the orange-ish of the Red-shafted Flicker. Thanks to Sunil Bhavsar for the use of his photos.
Source: SanDiegoRegionBirding Latest Reports