Notes on the Plumage of North American Birds 



SIXTIETH PAPER 



By FRANK M. CHAPMAN 



(See Frontispiece) 



Purple Grackle (Quiscalus quiscula quiscula\ Figs. 1-3). Nestling Grackks 

 are almost uniform sooty brown with traces of iridescence in the wings and tail. 

 In August this plumage is exchanged, by complete molt, for the glossy dress 

 of the adult bird. There is no spring molt and the slight difTerences between 

 winter and summer plumage are due to wear and exposure. The female (Fig. 3) 

 is smaller in size and duller in color than the male, somewhat duller, even, than 

 our figure. 



Florida Grackle (Quiscalus quiscula aglcEus, Fig. 4). The plumage changes 

 of this bird are similar to those of the Purple Grackle, from which it may 

 usually be distinguished by its smaller size, purple-violet breast, and bottle- 

 green back. 



Bronzed Grackle (Quiscalus quiscula aneus, Fig. 5). The nestling plumage 

 of this species resembles that of the Purple Grackle, and, as in that species, 

 the plumage of the adult is acquired at the fall (post-juvenal) molt. There is, 

 however, a more pronounced difference between the color of the winter and 

 summer plumage in the Bronzed, than in the Purple Grackle, the shining brassy 

 back and abdomen of the fall and winter Bronzed Grackle becoming dull seal- 

 bronze in summer. 



The Bronzed may be known from the Purple and Florida Grackles by the 

 absence of the iridescent bars which, whether exposed or concealed, are present 

 in the back and abdomen of the other two birds. 



The Relationships of Our Grackles 



The relationships of the Bronzed, Purple, and Florida Grackles is a classic 

 problem in North American ornithology. The case has been stated at length 

 by the wTiter in the Bulletin of the American Museum of Natural History, 

 (Vol. 4, 1892, pp. 1-20) to which the interested reader is referred. Briefly 

 there appear to be two species of Grackles in this small group: first, the Bronzed 

 Grackle, an exceptionally stable form, which, throughout a breeding range 

 extending from southern Texas to Labrador and west to the Rockies, apparently 

 shows no geographic variation in color; second, a variable species of which the 

 Florida Grackle is the southern form, the Purple Grackle (Fig. 2) the northern 

 form. When, however, the range of the Bronzed Grackle touches that of the 

 Purple Grackle (as it does from southern New England, the upper Hudson 

 Valley, and southward along the Alleghanies at least to Alabama), the two 

 intergrade producing a bird with a brassy green back (Fig. i), which is found 

 breeding only in this comparatively narrow area of intergradation. 



1 This is the nomenclature of the A. 0. U. ("heck-List. According to Ur. Obcrholser (see preceding article) 

 this name should be applied to the Florida Grackle. while the Purple Grackle should be known as Quiscalus quiscula 

 ridgwayi. The case has not yet been acted upon by the A. (). U. Committee on Nomenclature. 



(ig5) 



