NATURAL HISTORY OF THE SWAINSON'S WARBLER 45 



JUVENILE PLUMAGE 



The juvenile wings and tail are similar to those of adults. 

 Upperparts are brown; throat and chest are dark brown; and 

 other underparts are mottled brown and white. There is no 

 whitish line over the eye. 



GEOGRAPHIC VARIATION 



Breeding birds from the Southern Appalachians differ from 

 Coastal Plain birds in that underparts tend to be whiter (less 

 tinged with yellow) . The underparts of 15 Coastal Plain specimens 

 in breeding plumage were primrose yellow ; whereas seven moun- 

 tain specimens in breeding plumage were almost immaculate 

 below but had a light suffusion of napthalene yellow on breast and 

 abdomen. There is no significant size difference between these two 

 forms. 



The mountain form was described as a new subspecies by B. 

 Meanley and G. M. Bond (1950, p. 191-193) and is known as 

 Limnothlypis swainsonii alta (Appalachian Swainson*s Warbler). 

 The type specimen, adult male. United States National Museum 

 No. 362424, was collected at Walhalla, S.C., on June 25, 1940, by 

 W. M. Perrygo and S. Y. Hoyt (original number 4,681). 



MOLTING 



Virtually nothing is known of the molt of this species. M. G. 

 Vaiden (1940, p. 126) collected a male in partial molt on July 17, 

 1939, in Sunflower County, Miss. 



