Notes on the Plumage of North American Birds 



, THIRTY-NINTH PAPER 



Bv FRANK M. CHAPMAN 



(See Frontispiece) 



American Pipit {Anthus rubescens, Figs, i, 2). — The Pipit's variations in 

 plumage are mainly seasonal. The sexes are alike in color, and the nestling 

 differs from the winter adult chiefly in being somewhat more streaked above 

 and less buffy below. Birds in fresh fall plumage, that is, after the postjuvenal 

 molt in the young and postnuptial molt in the adult, are almost as buffy below 

 as birds in fresh spring plumage (Fig. 2), but the underparts are somewhat 

 yellower and the upperparts are much browner and less grayish, resembling 

 therefore Fig. i rather than Fig. 2. With the advance of the season the plu- 

 mage fades, the underparts become paler and more sharply streaked (Fig. 1 

 represents winter plumage, but is too yellow below) and the upperparts are 

 duller. 



In April, the body plimiage is molted (prenuptial molt) and the under- 

 parts now become pinkish buff, the upperparts grayish (Fig. 2). As with the 

 fall plumage, this spring plumage is also much affected by fading and wear, 

 and midsummer birds are much like midwinter birds below but are decidedly 

 grayer above. No geographic races of the Pipit are known. 



Sprague's Pipit (Anthus spraguei, Fig. 3). — The sexes are alike in color 

 in this species. The nestling resembles the adult below, but the feathers of 

 the central part of the back are conspicuously margined or ringed with white, 

 much as in the immature Baird's Sandpiper. Late-winter and early-spring 

 birds are paler, more worn than those of autumn. At the spring molt, which, 

 according to American Museum specimens, takes place in April, apparently 

 most of the body plumage is replaced by more richly colored feathers, and the 

 bird appears in a plumage resembling the bird figured (Fig. 3). As with the 

 American Pipit, this plumage also changes with wear and July specimens re- 

 semble those of January. There are no geographic races of Sprague's Pipit. 

 From the eastern Pipit, the only other member of the genus Anthus found in 

 North America, it differs most conspicuously in its streaked back and smaller 

 size. 



Alaskan Yellow Wagtail {Budytes flavus alascensis, Fig. 4). — The adult 

 female Yellow Wagtail differs from the adult male (Fig. 4) in having the gray 

 areas of the head darker and browner, and the back browner less brightly 

 olive-green, but these differences are not pronounced enough to warrant field 

 identification of the sexes by color alone. The nestling or juvenal plumage is 

 quite unlike that of the adult. The upperparts are dark brown with a suggestion 

 of black, the underparts buff with no hint of yellow. Black streaks border 

 each side of the throat and meet in a crescent on the breast. The first 

 winter plumage, which follows the juvenal, is nearly uniform grayish olive 



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