1S90.] Chapman. Change*, of Plumage in the Bobolink. 121 



of color in the feather? themselves, accompanied by a wearing 

 away of their more exposed portions, resulting in the breeding 

 dress with which we are familiar. That this is in part true, there 

 can be no doubt, but that this change is attended by a complete 

 moult, is apparently proved by the material before me. 



Before further discussing the subject it may be well to briefly 

 review the seasonal and sexual costumes assumed by the Hobo- 

 link. The nestlings of both sexes resemble each other and 

 differ from the bird of the year in having the entire plumage, 

 particularly below, of a more buffy color ; there is a necklace of 

 faint dusky spots across the breast and the flank streaks are 

 almost indistinguishable. This plumage is soon followed by the 

 well- known Reed-bird dress in which, perhaps, the males aver- 

 age slightly brighter. The black streaks on the Hanks and sides 

 are now clear and well defined, the feathers of the breast have 

 generally a small, black, basal shaft-streak, and a spot of the same 

 color occasionally appears on the feathers of the throat. In the 

 winter this plumage by fading and abrasion loses much of its 

 brightness and the bird then closely resembles the worn bleeding 

 female. It is not necessary in this connection to describe the 

 costumes of the adult female, nor have I material to fully discuss 

 the subject. As far as I know, the adult bird in the fall cannot 

 be distinguished from birds of the year. 



In calling attention now to the main object of this paper, the 

 costumes of the male bird, without at this moment dwelling on 

 his appearance in full nuptial dress, we will first consider the 

 change which follows the close of the breeding season. The 

 bird now undergoes a complete moult, losing his entire plumage 

 even to remiges and rectrices, and acquiring a new dress which at 

 first glance is very similar to that of the bird of the year. Closer 

 examination, however, shows well-marked differences. In the 

 adult bird the feathers of the crown, particularly those of the 

 median line, have larger black areas and are less regularly bor- 

 dered with brownish : the secondaries are not terminated with a 

 narrow" edging of white, and the tertials lack the whitish border 

 which- is generally seen on those of the young bird. ( )n the 

 sides and flanks the markings are somewhat heavier but resemble 

 those of the young bird, while the black basal areas on the 

 feathers of the throat and breast are larger and more numerous, 

 in some cases occupying the basal three fourths of the feather, 



