Notes on the Plumage of North American Sparrows 



EIGHTH PAPER 



By FRANK M. CHAPMAN 



(See frontispiece) 



Dickcissel {Spiza americana, Figs. 1-3). In adult plumage, the Dick- 

 cissel is a well-marked, distinct, easily identified species, but, in juvenal 

 plumage, it so resembles an English Sparrow that one is glad to refer to its 

 more pointed tail-feathers as an unquestionable distinguishing mark. The 

 primaries, secondaries, and tail-feathers of this plumage are retained, and 

 the balance molted as the bird passes into first winter plumage, when the 

 young male closely resembles the female (Fig. 2). The adult male, after the 

 usual postnuptial molt (Fig. 3), resembles the young male in winter, but has 

 a small, more or less veiled black throat-patch. 



The spring molt is largely restricted to the anterior parts of the body, the 

 gray crown and sides of the head, the yellow on the crown and over the eye, 

 the white chin and black throat-patch being of new feathers, while the feathers 

 which are retained fade into the grayer summer dress, in which young and old 

 look alike. 



Lark Sparrow {Chondestes grammacus grammacus; Fig. 4). In this species the 

 sexes are alike, and there is but little variation with age or season. The juvenal 

 plumage has the breast distinctly streaked with black, the crown is striped 

 like the back, and the chestnut head markings are wanting. iVccording to 

 Dr. Dwight, the postjuvenal molt is complete, and the first winter plumage 

 is practically indistinguishable from the winter plumage of the adult. Some 

 birds, in first winter plumage, however, have the chestnut head marks but 

 slightly developed. The prenuptial (spring) molt is confined largely to the 

 head, but the rest of the plumage becomes worn and faded, making summer 

 birds grayer than those in winter plumage. 



The Western Lark Sparrow (C g. strigatus), breeding from the eastern 

 edge of the plains westward, is somewhat paler than the eastern bird, and 

 is more narrowly streaked. 



Vesper Sparrow {Po(ecetes gramineus gramineus; Figs. 5,6). In this species 

 the sexes are alike. The juvenal passes into first winter plimiage (Fig. 5) by a 

 molt of the body feathers, and is then indistinguishable from the winter 

 adult. There is no spring molt, and the less-brown, more sharply marked 

 summer plumage (Fig. 6) is acquired by wear and fading. 



The Western Vesper Sparrow (P. g. confinis), of the western United 

 States, except the Pacific Coast, is similar to the preceding but is paler above 

 and has a more slender bill. The Oregon Vesper Sparrow (P. g. affinis) is similar 

 to the preceding but is smaller %\ith an even slenderer bill and a plumage 

 browner than that of P. g. gramineus. 



(89) 



