Birds of Indian Subcontinent

A Revision of the Mexican Piculus (Picidae) Complex

Publication Type:Journal Article
Year of Publication:1978
Authors:Baptista, LF
Journal:The Wilson Bulletin
Date Published:1978
ISBN Number:00435643
Keywords:Colaptes, Colaptes aeruginosus, Colaptes auricularis, Colaptes rubiginosus, Corvidae, Corvus, Corvus corone, Corvus tristis, Picidae, Piculus, Piculus aeruginosus, Piculus auricularis, Piculus rubiginosus
Abstract:Variation in the Mexican representatives of the genus Piculus was studied in order to determine the status of the described forms (species and subspecies). A qualitative analysis of museum specimens representing population samples was presented along with quantitative data including statistical treatments of bill, wing, and tarsus measurements. The status of Piculus auricularis sonoriensis Van Rossem and Hachisuka was discussed: the type and a topotype examined did not differ from samples taken in neighboring states as indicated by the authors. However, northern samples of Piculus auricularis from Sonora to Colima were separable from material from Guerrero and Oaxaca on the basis of size and color. Two races are thus recognized. Variation in Piculus aeruginosus Malherbe was studied and evidence was presented suggesting genetic continuity and introgression with P. r. yucatanensis so that it is here regarded as a race of rubiginosus. Two races of Piculus rubiginosus are recognized for Chiapas, maximus of the Pacific Cordillera and yucatanensis of the Atlantic lowlands, separable on the basis of coloration and wing length. All the forms of Piculus in the Mexican check-list (Miller et al. 1957) are thus recognized with some changes in geographic distribution; these were divided into 2 species complexes including the gray crowned auricularis forms occupying the more xeric west and the slate crowned rubiginosus races of the more mesic east and southeast. In aeruginosus and auricularis size decreased clinally from north to south and intensity of coloration was found to increase in a clinal fashion in the same direction in accordance with Gloger's rule. Manifestation of Gloger's rule was discussed as being possibly the result of selection for crypticity. Both laws seem to operate locally in Chiapas to produce the larger, lighter colored highland race maximus. Size dimorphism between the sexes was found to decrease from north to south in both species complexes. Size dimorphism was most pronounced in bill length in all but one form (yucatanensis). The possible ecological significance of these findings was discussed.
Short Title:The Wilson Bulletin
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith