Vol. XXIV, pp. 31-36 February 24, 1911 



PROCEEDINGS 



of Tin: 



BIOLOGICAL SOCIETY OF WASHINGTON 



DIAGNOSES OF SOME NEW FORMS OF PICIDjEj 

 BY ROBERT RIDGWAY. 



[By permission of the Secretary of the Smithsonian Institution.] 



Colaptes auratus borealis subsp. nov. 



Type from Nulato, lower Yukon R., Alaska. Xo. 49,922, U. S. Nat. 

 Mus. Adult male. June 23, 1867. W. H. Dall. 



Similar to C. a. auratus and C. a. luteus in coloration, but decidedly 

 larger than the latter, much larger than the former. Adult male (type): 

 Wing, 170; tail, 113; exposed culmen, 36.5; tarsus, 30; outer anterior 

 toe, i':;. 



The case of Colaptes auratus is precisely parallel to those of Dryobates 

 villosus and D. pubescens, all three species gradually increasing in size from 

 the extreme southern to the extreme northern parts of their range, without 

 material change in coloration. Evidently the three cases require identical 

 treatment; and since three forms seem to best express the conditions in the 

 two species of Dryobates (east of the Rocky Mts.) we can not have less 

 than three forms of Colaptes without being conspicuously inconsistent. 

 While ( 'olaptes auratus luteus Bangs includes both the medium-sized speci- 

 mens from the more northern portions of the United States and the very 

 large ones from the far North, the type is an example of the resident bird 

 of .Massachusetts, though an exceptionally large one. Under the circum- 

 stances, it seems best to restrict the name luteus to the mid-region form, 

 and give a new name to tbe large northern bird. By so doing, we have, as 

 in the cases of Dryobates villosus and D. pubescens, a small Lower Austral or 

 Austrori parian form, a medium-sized form of the Upper Austral and Tran- 

 sition life-zones, and a large form in the Canadian and Hudsonian zones. 



Tbe case of Phlaiotomus pileatus, in its variations east of the Rocky 

 .Mountains, is nearly the same, but different in this respect: The species 

 does not extend so far northward, and the lines separating (somewhat 

 arbitrarily, as in the other species) the ranges of the two more southern 

 forms are shifted farther southward; the extreme southern form, instead 

 of inhabiting the Lower Austral zone as a whole, being restricted to middle 

 and southern Florida. 



9— Proc. Biol. Soc. Wash., Vol. XXIV, 1911. 



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