This is a male with red on the crown. Nuttall's Woodpecker is close to being a California endemic with just a small range extension into Baja, Mexico and a few controversial claims from Oregon. It inhabits Oak Woodlands.

This species is similar in appearance to Ladder-backed Woodpecker, but is generally darker. Cf. my photo of Ladder-backed Woodpecker in Texas. Their vocalizations are very different.