Golden-fronted Woodpecker (Melanerpes aurifrons) - HBW 7, p. 449

Taxonomy: Picus Aurifrons Wagler, 1829, Hidalgo, Mexico.
Sometimes combined with other barred congeners in a separate genus Centurus. Forms a superspecies with M. hoffmannii, and sometimes regarded as conspecific. Hybridizes with latter in S Honduras (R Pespire), with M. carolinus in S USA (Texas) and infrequently with M. uropygialis in SW Mexico. Geographical variation complex, and strong clinal variation in many plumage characters, making delimitation of races very difficult; in addition, mainland races, themselves variable to greater or lesser extent, intergrade, producing many populations with intermediate characters; grateloupensis possibly no more than an intergrade population. Subspecific treatment has varied greatly in the past, and some authors have recognized only 9 or fewer races; conversely, others have grouped races to form up to 4 separate species; further study needed. Paler birds from C Texas S to W Mexican Plateau described as race incanescens, but considered better merged with nominate; others from interior Chiapas described as race frontalis, tending towards nominate, but better treated as part of polygrammus. Twelve subspecies recognized.