Vol.^xivj Chapman, Sprii/g- Moult of the Bobolink. jc-^ 



find a single new white feather in this or any part of the bird's 

 pkimage. I do find, however, new black feathers appearing, and 

 there is in my mind, no doubt but that in due time these yellowish 

 white feathers of the fall plumage would have been replaced by 

 the black ones of the spring plumage. 



And this brings me to Dr. Chadbourne's statement that these 

 white feathers and a " chestnut shading " are evidence of albin- 

 ism in the Corumbd specimen, neither of them being shown in 

 his cage-bird. As for the white feathers in the abdomen, allow- 

 ing for a slight fading and abrasion due to their having been 

 worn for a longer time, they are exactly like those found in 

 the same part of several Reedbirds in the collection of the 

 American Museum. In other words, they appear perfectly 

 normal and are in no way albinistic. The "chestnut shading" 

 mentioned by Dr. Chadbourne as an evidence of albinism in the 

 Corumbil bird, and as not shown by his cage-bird, I am unable 

 to detect. In any event, it is obvious that the two birds are not 

 comparable. With the exception of the white abdominal area the 

 few old feathers remaining in the plumage of the Corumbd bird 

 do not materially effect its color, which is that of the newly 

 grown feathers, while Dr. Chadbourne's cage-bird was acquiring 

 its spring dress not by moult, but by change of color in the old 

 feathers. I think, therefore, that Dr. Chadbourne is mistaken 

 when he states that the Corumba bird is " apparently a partial 

 albino," and I must again assert my belief that this bird is 

 acquiring its breeding plumage by a complete moult. 



Admitting this, it may be said that one moulting specimen does 

 not prove that all wild Bobolinks moult in the spring, and, in 

 replying to this objection, I am very glad to find that Dr. Chad- 

 bourne and myself are in accord as to what constitutes evidence 

 of spring moult in the Bobolink. Speaking of his cage-bird 

 he says : " The buff edging of the breast feathers was never more 

 than a narrow line, evidently owing to the absence of the long 

 fugaceous tips, which are so characteristic of the newly developed 

 feathers, and it is therefore probable that spring males showing 

 much buff suffusion beneath have recently passed through a 

 * spring moult,' or at least through a partial feather change." It 

 is these tips which give the freshly moulted Corumbd bird so 



