112 U. S. NATIONAL MUSEUM BULLETIN 211 



paler around the edges. The autumn plumage acquired by the 

 juvenal females is much the same as that of the adult females." 



Ridgway (1902) describes the immature male in first-winter plumage 

 as "similar to the winter female, but larger; general color darker 

 (nearly black on pileum, auriculars, and orbital region) ; superciliary 

 stripe deeper ocher yellow; malar region, chin, and throat chrome 

 yellow, and chest dull cadmium yellow or orange-ochraceous ; no white 

 streaks on breast; primary coverts narrowly tipped with white." 



This plumage is worn without much change until the first post- 

 nuptial molt the following summer. Apparently, young males do 

 not breed in this plumage. 



Young females in first winter plumage are much like the adults, 

 but colors and more veiled; the breasts are streaked with dull whitish; 

 they evidently breed the following spring, when less than a year old. 



The prenuptial molt of adults and young, is apparently very 

 limited, confined mainly to the region of the head and neck, the 

 nuptial plumage being produced chiefly by the wearing away of the 

 dusky tips of the autumn plumage. A complete molt occurs in late 

 summer, at which the fully adult plumages are acquired. In the 

 adult male the bright yellow, or orange, of the head and neck is 

 obscured, sometimes nearly concealed, by dusky tips; and in the adult 

 female the colors are duller, less distinct, and the white streaks on the 

 breast are less clear. 



The adult male in his nuptial plumage is a handsome bird; Ridgway 

 (1902) describes a high-plumaged male as having "head, neck, and 

 chest yellow or orange (varying from canary yellow to almost cadmium 

 orange, rarely to saturn red) ; lores, orbital region, anterior portion of 

 malar region, and chin black; rest of plumage uniform black, relieved 

 by a white patch on the wing, involving the primary coverts (except 

 their tips and shafts) and portions of the outermost greater coverts; 

 anal region yellow or orange." 



Food. — Beal (1900) analyzed the contents of 138 stomachs of the 

 Yellow-headed blackbird: 



As indicated by the contents of these stomachs, the food for the seven months 

 [April to October, inclusive] consists of 33.7 percent of animal (insect) matter and 

 66.3 percent of vegetable matter. The animal food is composed chiefly of beetles, 

 caterpillars, and grasshoppers, with a few of other orders, while the vegetable 

 food is made up almost entirely of grain and seeds of useless plants. Predaceous 

 beetles (Carabidae) constitute 2.8 percent of the season's food, . . . other beetles 

 a little more than 5 percent . . . 



Caterpillars constitute 4.6 percent, but nearly two-thirds of them are taken in 

 July, and in that month they form 21.5 percent of the month's food. Remains of 

 the army worm (Leucania uniptmcta) were identified in 6 stomachs. 



Grasshoppers are eaten to the extent of 11.6 percent for the season, 

 but mainly after August. "The remainder of the animal food, 9.7 



