^"Is^'^l Chapman, Spring Moult of the Boholuik. I c; I 



It is of course well known that cage-birds may moult very 

 irregularly, and this is particularly true of Bobolinks. Dr. Allen^ 

 records numerous individuals moulting in the spring while Dr. 

 Chadbourne's specimen lost practically no feathers at that season. 

 In a bird store in New York City at this time (November) are two 

 male Bobolinks still wearing the black breeding dress. Before 

 admitting, therefore, that the changes which occur in the plumage 

 of a cage-bird may also take place in birds in a state of nature, it 

 will be well to examine that part of Dr. Chadbourne's paper 

 relating to the specimens of wild Bobolinks he has studied. This 

 refers largely to the CorumbA, Brazil, specimen (Am. Mus. No. 

 32783) figured in a previous number of this journal.- In 

 describing this specimen,^ I have said that it was passing from 

 the Reedbird to the black Bobolink plumage by a complete moult. 

 In fact the only feathers of the old plumage remaining are the first 

 primary and five inner secondaries of the right wing, four inner 

 secondaries of the left wing, the primary coverts and scapularies 

 of both wings, and some of the under wing-coverts. Old contour 

 feathers may be found in the centre of the back and in small 

 numbers about the head, neck, and upper breast. In all these parts 

 the moult is in progress and these old feathers would evidently 

 soon have been replaced by those of the new plumage. The 

 centre of the lower breast and the centre of the abdomen are still 

 occupied by the old plumage, the feathers of this part being, as in 

 the adult Reedbird, white tinged with yellow. An August moult- 

 ing, adult Bobolink has nearly acquired the Reedbird plumage but, 

 as in the CorumbA bird, the feathers of the middle of the abdomen 

 have not as yet been moulted, apparently showing that these 

 feathers are the last to be shed. 



' Bull. Am. Mus. Nat. Hist., VIII, 1S96, p. 44. 



'^ The Auk, X, 1893, p. 309. Dr. Chadbourne'.s remarks upon this plate 

 (atitea, p. 141) would imply that acting under my instructions, the artist had 

 partially completed the moult of the Corumbd bird therein figured, and I must 

 confess that my own statement regarding it would lead one to the same con- 

 clusion ; but as I was not in this country when either the drawing or lithograph 

 was made and, beyond the fact that the plate was contemplated, knew nothing 

 whatever about it, I can hardly be held responsible for its inaccuracies. 



3 The Auk, VII, 1890, p. 120. 



