Vol. XIV 
Rea | CHADBOURNE, Sfring Plumage of the Bobolink. 139 
The possibility of a spring ‘moult’ being entirely overlooked is 
worth considering at this point. If we assume for the moment 
that none of the old feathers change to the color of the breeding 
dress, and that all which are unlike those of the preceding 
plumage, have replaced old feathers already ‘moulted,’ can we 
then form any idea of the loss during the development of the 
spring dress of the male Bobolink? In other words, how many 
feathers would a Bobolink lose during a complete ‘moult’? I 
have tried to estimate this approximately in a male Bobolink, 
killed May 30, by carefully pulling out, one by one, all the contour 
feathers from the two ventral feather-tracts, including the ‘ inner 
lateral,’ but neither the ‘humeral’ nor the ‘gular tracts’ of 
Nitzsch;! and then gluing each separately on sheets of paper. 
Both my patience and mucilage gave out by the time I had 
finished the sheets in question,— about one third of the under 
parts of the bird.2. The contour feathers on the sheets amounted 
to 439 in all, none of which, judging from their color alone, could 
have formed a part of the winter dress. The feathers on the 
upper breast, neck, and throat are smaller, and must be relatively 
more numerous ; and it is certainly safe to estimate the total loss 
from the abdomen, breast, and throat, at three times actually 
counted, making the total 1317. The back and upper parts must 
increase this number by at least one half; and ‘he hypothesis of a 
‘moult without color-change’ would therefore imply a loss of 2634 
Jeathers for the development of the full spring plumage of the male 
Bobolink. 
If the process lasted from three to six weeks —(it was three 
weeks from the time the first black spot appeared, until the 
full plumage of my Bobolink has been attained by color-change 
'Pterylographia. (English translation by Sclater.) Publications of the Ray 
Society, London, 1867, p. 26, seq. 
°It will be noticed that in this estimate the plumage of the head, wings, 
legs, and tail has not been included. The flight feathers, because they are 
often broken accidentally, and cast off by cage-birds when not ‘moulting’; 
those of the head and legs, because they are so small as to be easily over- 
looked; while by omitting the remainder of the wings and tail, and counting 
the total loss from the upper parts as only one half that from the gastraum, 
my result must be an underestimate. 
