COLAPTES. 403 



{Ferrari-Perez), Chupadero, San Jose, Concepcion, Chihuahua city, Temosachic, 

 all in Chihuahua (W. Lloyd), Ciudad in Durango (A. Forrer), Sierra de Bolanos, 

 Sierra de Xeres, Sierra de San Luis Potosi, Sierra de Calvillo, Aguas Calientes, 

 Sierra de Nayarit, Sierra Madre de Tepic {W. B. Eichardsm), Zapotlan [W. 

 Lloyd), Guanajuato (Buges^), Tetelco, Chimalpa, Ixtapalapa, Huipulco, in the 

 Valley of Mexico (Ferrari-Perez), Valley of Mexico (Herrera i* ^^j, Temiscaltepec, 

 Eeal del Monte {Bullock i), S. Miguel Molino, Texmelucan 9, Totimehuacan ^, in 

 Puebla (Ferrari-Perez), Ixtaccihuatl, Popocatepetl (Baker ^% Volcan de Colima 

 ( W. Lloyd), Omilteme in the Sierra Madre del Sur, Guerrero (Mrs. E. H. Smith), 

 Las Vigas (Ferrari-Perez), Suapam (Salle % Jalapa (de Oca^), Orizaba (Baker ^% 

 Monte Alto (Sumichrast '^), Cofre de Perote (Sumichrast ^ M. Trvjillo), La Parada 

 (Boucard ^), Totontepec, Tonaguia, Villa Alta (M. Trvjillo) *. 



Colaptes mexicanus was described by Swainson from specimens obtained by Bullock 

 at Temiscaltepec and Eeal del Monte in the tablelands of Central Mexico i, and it has 

 since proved to be a common species all over this region wherever a suitable country 

 exists. Its northern extension reaches far beyond the limits of Mexico, and spreading 

 from the base of the Rocky Mountains to the shores of the Pacific stretches to Sitka in 

 the far north-west. The birds from this distant region, according to Mr. Eidgway, 

 present some slight differences, and are his C. cafer saturatior. Within the limits of 

 Mexico some variations also exist, but these cannot well be traced to definite localities ; 

 the differences seem all due to some slight shades- of colour and of dimensions. Birds 

 from our northern frontier States are generally paler and greyer above, whilst those 

 from Oaxaca are darker and redder, especially on the head, the birds from the table- 

 lands being intermediate. 



A point of considerable interest is associated with this species as regards its relations 

 with Colaptes auratus along their common boundary. It was long ago shown by Baird 

 that a strip of country between the ranges of the two birds is occupied by a mixed 

 form, which he called G. hybridus, believing it to be the result of the interbreeding of 

 the two definite species. This interpretation of the facts has been adopted by several 

 writers as the most probable explanation of them. Mr. Hargitt, in his 'Catalogue,' 

 accepted this view, and from his treatment of the subject Mr. Allen was induced to 

 examine a very large number of specimens, with the result that he came practically to 

 the same conclusion. But the question cannot be considered settled, for the difficulty 

 in accepting the hybridization-theory suggested by Dr. Couesf still remains unex- 

 plained. 



Though C. auratus approaches our boundary in Texas, we are not aware that it 



* Mr. Allen's map gives Tehuantepec as within the breeding-range of C. meaneanus, but without authority. 

 We have not traced the bird beyond the uplands of Oaxaca. 

 t Birds N.-W. p. 293. 



51* 



