BIRDS OF NORTH AND MIDDLE AMERICA. 



203 



Young male. — Similar to the adult male, 

 nuchal patch, the crown, however, streaked 



but without any red 

 or spotted with red 



Footnote— Continued. 



Locality. 



FEMALES— continued . 



One adult female from northeastern Illinois, September (D. v. 



villosiis) 



One adult female from northern Virginia, January (Z>. v. 



villosus) 



One adult female from southwestern Indiana, May (D. v. 



villosus?) ; 



Two adult females from southeastern Illinois, April (D. v. 

 auduhonii?) 



One adult female from southeastern Missouri, June (Z). v. 

 villosus) 



One adult female from Arkansas, October (D. v. villosus?) 



Four adult females from Louisiana, January, April {D. v. 

 auduhonii) 



One adult female from Mississippi, September (D. v. auduhonii?) 



Seven adult females from North Carolina January-Septem- 

 ber (i>. V. auduhonii?) 



Four adult females from South Carolina, March, April, Decem- 

 ber (D. V. auduhonii) 



Four adult females from Georgia, February, April (Z). v. 

 auduhonii) 



Eight adult females from Florida {D. v. auduhonii) 



Outer 

 ante- 

 rior toe. 



14.5 



14 



14 



13.5 



13 

 13.5 



14.2 

 13 



13.4 



13.5 



13.4 

 13.1 



The above measurements show how difficult it is to subdivide this species satis- 

 factorily into two or more subspecies according to size. The transition from the 

 smallest specimens, found in Florida and along the Gulf coast to Texas, to the largest, 

 found in Mackenzie and Yukon, is so very gradual and the attendant change in colora- 

 tion so very slight that subdivision with definite characters is practically impossible. 

 The difference in size between extreme northern and southern specimens is very 

 great, but it is almost impossible to satisfactorily define subspecies, whether only 

 two or several, or to satisfactorily limit their respective ranges. The difficulty is 

 enhanced by the lack of anything like adequate material; for, the species being 

 more or less migratory over much the greater part of its range, comparison of speci- 

 mens should be restricted to those taken in or near the breeding season, possible 

 migrants being eliminated. Unfortunately a great majority of the specimens in 

 collections are winter, late fall, or early spring birds, and therefore are of only second- 

 ary use for the purpose in view. The value of measurements of the wing and tail 

 is greatly vitiated if both winter and summer or late spring specimens are included 

 together, since there is considerable difference owing to abrasion of the tips of the 

 remiges and rectrices. Besides exercising care in these matters, it is necessary also 

 to separate specimens from different faunal areas within a given State, for there is 

 much difference in size between birds from the coast lowlands and those from the 

 interior mountainous districts of Pennsylvania, Maryland, Virginia, and the Carolinas, 

 for instance, as also between those from eastern and western Tennessee and Kentucky, 

 southern and northern Indiana and Illinois, etc. 



The author admits his inability to offer a satisfactory treatment of the subject, 

 which can only be done when the necessary material can be brought together. 



The case is quite the same as that affecting D. pubescens, Colaptes aurafus, Phloco- 

 tomus pileatus, and other birds which undergo a gradual increase of size from Florida 

 and the Gulf coast northward, without accompanying material change in coloration 



