YELLOW-HEADED BLACKBIRD 111 



were found mixed with occasional water moss. The third day showed 

 little change in the menu, but the food was less digested and, on this 

 day, occasional meals of fresh food began to supplant the regurgi- 

 tated." 



The nesting success in the 504 nests studied by Ammann (MS.) 

 was not so good as that reported by Fautin (1941b). The 504 Iowa 

 nests contained 1,565 eggs, an average of 3.1 eggs per nest. "Of the 

 173 successful nests, 40 were completely and 133 partially successful, 

 an average of 2.5 young were raised. Eggs hatched in 44.2 percent 

 of the nests and young were fledged in 34.3 percent. Of all the eggs 

 laid, 53.6 percent hatched and 27.5 percent became successfully 

 fledged young. In comparing the nesting success of this species with 

 others it is found to be much lower in every respect. The percentage 

 of eggs hatched and 3 r oung fledged of 481 nests of six other species 

 of passerine birds is 61.4 and 43.0, respectively." 



Fred G. Evenden, Jr., writes to me that he found a yellow-headed 

 blackbird's nest in a swamp near Corvallis, Oreg., that had been 

 thoroughly torn up by northwestern redwings that nested in abund- 

 ance in the swamp, and says that "the yellow-heads were not toler- 

 ated by the redwings, being chased and attacked whenever they were 

 in the swamp area." 



Plumages. — The small nestlings are only thinly covered with 

 buffy down on the feather tracts of the head and back, but the first 

 plumage soon begins to appear, pushing the down out on the tips of 

 the feathers, where it persists longest on the top of the head. Chap- 

 man (1921a) gives the best description of the juvenal plumage of the 

 3^ellow-headed blackbird as follows: "The whole head and breast are 

 warm buff, giving the effect of a brown-headed bird; the abdominal 

 region whitish; the back blackish, both more or less fringed with buff; 

 the tail and wings black, the wing-coverts tipped with white. At the 

 post-juvenal molt the tail and wing-quills are retained, while the rest 

 of the plumage is exchanged for a costume which resembles that of 

 the female, but is usually without streaks on the breast, or if streaks 

 are present, they are yellow." I think this description must refer to a 

 young male, for the female has no white in the wings. 



Fautin (1941a) says: "The first-winter plumage of the young is 

 acquired b} T a partial post-juvenal molt as a result of which the buffy 

 feathers of the head, neck, and breast regions of the fledglings are 

 replaced in the males by yellowish feathers tipped with brownish on 

 the sides of the head, throat, and breast, with a collar sometimes 

 extending around the back of the neck. The feathers of the back 

 nape, crown and wings are a deep brown while those of the under 

 parts and especially those of the belly and crural regions are somewhat 



