70 BULLETIN 203, UNITED STATES NATIONAL MUSEUM 



two well-marked wing-bars ; chin and throat brownish white tinged with yellow ; 

 sides of jugulum smoke gray, its center yellowish; sides of breast gamboge 

 yellow shading into olive on the flanks ; middle of breast, with most of abdomen, 

 yellowish white; under tail-coverts ashy white. All the feathers on the under 

 parts which are strongly yellow or olive, and those on the upper parts which 

 are decidedly ashy or greenish, appear to belong to the autumnal plumage or, 

 as it is now called, the first winter plumage, but all the other feathers on the 

 head and body are evidently those of the first plumage. * * * 



I have not seen the young female Bachman's Warbler above referred to, but 

 Mr. Wayne writes me that "it differs from the male only in these respects: 

 The yellow on the sides of the breast is very much paler and more restricted and 

 the back is not greenish, but brownish. The white on the tail-feathers is merely 

 indicated on the margins of the inner webs of the tail-feathers." 



It would appear from the above that there is a sexual difFerenc© 

 even in the ju venal plumage, and that the postjuvenal molt begins 

 before the middle of May. This molt evidently involves all the con- 

 tour plumage and the wing coverts but not the rest of the wings or the 

 tail. The young male in first winter plumage is similar to the adult 

 male at that season, but the crown is entirely gray, or with very little 

 black; the feathers of the black patch on the throat, which is more 

 restricted, are tipped with yellowish or buffy. There are no specimens 

 available that indicate a prenuptial molt, which is probably very lim- 

 ited. Young males in the first nuptial plumage may be recognized 

 by the worn and faded wings and tail. 



The complete postnuptial molt of adults apparently occurs in July 

 or earlier ; I have seen no molting birds, but a large series of August 

 birds are all in completely fresh winter plumage. In this plumage 

 the male resembles the spring male, but the black of the crown is 

 widely tipped with gray and the black of the breast is narrowly tipped 

 with yellowish; these tips largely wear away before spring, although 

 Wayne (1910) says that his "breeding males all show the olive yellow 

 edging on the black feathers." Similar molts and changes take place 

 in the female, but she has no black in the crown and much less or none 

 at all on the breast ; her colors are duller and she has less white in the 

 tail, as well as olive-green, instead of yellow, lesser wing coverts. 



For a full description of individual variations in plumage, the reader 

 is referred to Mr. Brewster's (1891) excellent paper.] 



Food. — Very little information is to be found concerning the food 

 of this warbler, but insects undoubtedly constitute its diet. Howell 

 (1924) says: "Five stomachs of this species from Alabama contained 

 remains of caterpillars and a few fragments of Hymenoptera, prob- 

 ably ants." 



Behavior. — ^Wayne (1907), in writing of this bird on its breeding 

 grounds, says : "Bachman's Warbler is a high-ranging bird, like the 

 Yellow-throated Warbler, and generally sings from the top of a 



