136 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



den until forced to run, when theybecome very lively. They are fed 

 by their parents until able to fly and forage for themselves. 



tPlv/mages.— The downy young have at least two distinct color 

 phases, both of which are often found in the same nest. In the gray 

 phase the upper parts are "smoke gray" or "pale smoke gray"; 

 in the buffy phase the upper parts are " pinkish buff " or " vinaceous 

 buff." They are lighter below and almost white on the breast ; they 

 are distinctly spotted with " hair brown " or " sepia " on the head and 

 neck, and more faintly mottled with the same color on the back; 



The juvenal plumage is not fully acquired until the young bird is 

 about fully grown, the down disappearing last on the chest and 

 thighs. The upper parts are heavily and boldly mottled; each 

 feather of the back, scapulars, lesser wing coverts, and tertials is 

 centrally dusky, broadly tipped, and margined with " pinkish buff," 

 most conspicuously on the scapulars. The greater wing coverts are 

 largely "gull gray," becoming dusky near the tips, and some are 

 tipped or edged with buffy. The primaries are mostly black, with 

 narrow white tips ; the tail is largely " gull gray," somewhat mottled, 

 and with a broad subterminal band of dusky, tipped with white 

 or buffy white. The tail is never wholly dusky, as in the young 

 California gull, a good diagnostic character. The under parts are 

 largely white ; the crown and breast are heavily mottled with dusky, 

 and the sides are barred with the same. The bill is dusky, with the 

 inner half of the lower mandible light yellowish. 



Except for a molt of some of the body plumage, the first winter 

 plumage is a continuation of the juvenal; the buffy edgings fade 

 out to white and wear away ; many new feathers, partially " gull 

 gray" with dusky markings, come in on the back; and the dusky 

 markings fade and wear away or are replaced by white on the 

 breast and head during the winter. A partial prenuptial molt in- 

 creases the amount of white on the head and under parts. 



A .complete postnuptial molt produces the second winter plum- 

 age, in which the back is mainly or wholly " gull gray," the feathers 

 narrowly edged with whitish, and the greater wing-coverts are 

 largely the same; the lesser wing-coverts are still mottled with 

 dusky ; there is much dusky in the tertials and secondaries, and the 

 primaries are plain brownish black. The tail is whiter basally, but 

 has a broad subterminal dusky band. The head and neck are heavily 

 streaked and spotted with dusky, but the under parts are mainly 

 White. The inner half of the bill is yellowish and the outer half 

 black. The partial prenuptial molt produces pure white under 

 parts and nearly a pure white head, with a clear "gull gray" back. 



At the next complete molt, the second postnuptial, when the 

 bird is 2 years old, the fully adult plumage is perhaps assumed by 

 some birds ; but many, probably a decided majority, still retain signs 



