22 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



skirts of the town and on the beaches, where they evidently found an 

 abundance of food. 



Plumages. — Ridgway (1904) notes no sexual difference in the 

 Juvenal plumage, which he describes as "above olive-brown, the wings 

 and tail as in the autumnal plumage; superciliary stripe, malar stripe, 

 and under parts pale yellowish buff, relieved by a conspicuous crescentic 

 patch on chest of sooty black, connected laterally with a submalar stripe 

 of the same color along each side of the throat; bill, legs, and feet 

 brownish." 



The postjuvenal molt takes place between July and September. This 

 involves some wing coverts and all the contour plumage, but not the 

 rest of the wings or the tail. It produces a first- winter plumage, which 

 is practically like that of the adult. Ridgway (1904) describes the 

 young male in this plumage as "above plain olive, more grayish on head 

 and rump ; wings and tail as in adults ; superciliary stripe, chin, and 

 throat pale straw yellow, the first two paler, nearly white ; rest of under 

 parts pale buffy yellow or yellowish buff, paler (nearly white) on un- 

 der tail-coverts ; chest tinged with brown, and with a distinct crescentic 

 patch of darker brown ; sides and flanks light grayish brown or olive." 

 He describes the young female as similar, but "chest less strongly tinged 

 with brown and with only a few spots of darker brown." 



As with some of the Eurasian races, there is probably quite an 

 extensive prenuptial molt in birds of all ages, which involves all the 

 contour plumage, most of the wing coverts and the central tail feathers, 

 though we have not the material to show it in our subspecies. Adults 

 have a complete postnuptial molt, beginning late in July and sometimes 

 lasting through September. There seem to be no winter specimens 

 available that are definitely known to belong to this subspecies, but the 

 winter plumages are probably similar to those of closely allied races, 

 which are fully described in Witherby's Handbook ( 1919) . 



Food. — Not much is known about the food of the Alaska yellow 

 wagtail, which probably does not differ materially from that of the 

 species elsewhere. Witherby's Handbook (1919) says that the food 

 of the European race consists "almost entirely of insects (coleoptera 

 and larvae, diptera, orthoptera, larvae of lepidoptera, rhynchota, etc.). 

 Saxby records small worms, larvae, aquatic insects, and small univalves, 

 but these are probably exceptional and diptera constitute bulk of food." 



Dr. Grinnell (1900) saw some of these wagtails feeding on salmon- 

 berries, which grew plentifully near the alder thickets. He says also : 

 "Several came around our tents at Mission Inlet daily for crumbs, and 

 if I kept quiet they would come quite close. A wagtail would approach 

 from the nearest grass-patch, sidling along, hopping daintily with ever- 

 changing attitude and canting its head from one side to the other. At 

 every step or two the bird would hesitate a moment before again ad- 

 vancing, its tail nervously twitching up and down. If it spied a crumb, 



