More than thirty years ago, when our knowledge of variation was far less than it is now, Dr. Stejneger had the discernment to interpret Colaptes auratus (Linnaeus), Colaptes cafer (Gmelin), and Colaptes hybridus (Baird) to be dichromatic or trichromatic phases of one species, and not two species that hybridize on a gigantic scale.
Source: tatoeba (12353671)