Notes on the Plumage of North American Birds 



FORTY-FOURTH PAPER 



By FRANK M. CHAPMAN 



(See frontispiece) 



Purple Martin (Progne subis, Figs, i, 2). — As the plate figuring a pair of 

 this species clearly shows, the adult male and female may be readily distin- 

 guished, but the young male, even in its first breeding plumage, cannot, at a 

 glance, be distinguished from the female. 



In its nestling, or juvenal plumage, the male is essentially like the adult 

 female. This plumage it retains until after it leaves us for the South. Some 

 time during the winter the postjuvenal molt occurs, and the bird acquires its 

 first breeding plumage. This bears a general resemblance to that of the female 

 but has a scattering of the steel-blue feathers of the adult male, which are 

 more conspicuous in the gray underparts than above. At the succeeding molt, 

 which also takes place after the bird migrates, and doubtless therefore in its 

 winter quarters, the adult steel-blue plumage is acquired. 



It is interesting to note that Martins and Swallows, birds which make 

 extended migrations, leave for their southern homes before gaining the fresh 

 set of feathers which we might imagine they would require before embarking 

 on their long journey. Possibly their aerial habits leave their plumage so 

 little worn, that even after breeding it is still serviceable and, unlike that of 

 vegetation-haunting species, in condition to meet the demands made by mi- 

 gration. 



The Eastern Purple Martin {Progne subis subis) is found locally through- 

 out the United States and southern Canada, except on the Pacific coast 

 where it is replaced by a closely related race, the Western Martin (Progne 

 subis hesperia), the male of which resembles the same sex of the eastern bird, 

 but the female is decidedly paler and whiter below than the female of Progne 

 subis subis. 



Gray-breasted Martin {Progne chalybea, Fig. 3). — The Gray-breasted 

 Martin is a species of tropical America which ranges as far north as Texas. 

 It is smaller than our North American Martin, but both sexes so closely re- 

 semble the female of that species that for many years Texas specimens of 

 chalybea were considered to be Purple Martins. Their true identity was made 

 known by Mr. W. De Witt Miller ('The Auk,' XXIII, 1906, p. 226). 



Barn Swallow {Hirundo erythrogaster, Figs. 4, 5).^ — The male Barn Swal- 

 low averages brighter in color and, in some cases, has a longer tail than the 

 female, but the sexes are often alike in color and size and cannot therefore be 

 distinguished by external characters. 



The young bird (Fig. 5) on leaving the nest is much paler below and duller 

 above than the adult, and the outer tail feathers, which, when fully grown add 

 so much to the appearance of the Barn Swallow, are not more than half an 



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