House Finch (Carpodacus mexicanus) - HBW 15, p. 585

Taxonomy: Fringilla mexicana Statius Müller, 1776, Valley of Mexico, Mexico.
Geographical variation complex, and considerable variation in body size, bill size and shape, and wing, tail and tarsus lengths; also, degree of saturation of red in male plumage (largely derived from access to carotenoid pigments in food) highly variable both within and among populations (in some populations in Hawaiian Is, where introduced, males lack red); in addition, some populations poorly known and range of variation undescribed. Large races mcgregori (extinct) and amplus sometimes considered to represent one or perhaps two separate species. Conversely, in SW USA, proposed races grinnelli (described from R Scott, NW of Callahan, in California), solitudinus (from Fallon, in Nevada), smithi (from near Aurora, in NC Colorado) and anconophila (from Chinati Mts, in Presidio County, in SW Texas) all commonly synonymized with frontalis. Present division of races, based on male plumage and morphological features, may not be sustainable, and entire range of variation within the species requires further research. Eleven extant subspecies currently recognized.