366 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



in the shrubbery. They are odd, pale little birds when we first see 

 them in July, not long from the nest — light brown on the back, with 

 a wash of yellow on the breast and flanks, and hoary about the head, 

 almost white, although they soon lose this latter mark. A. Dawes 

 Du Bois (MS.) remarks: "The plumage of the fledglings is so pale 

 that they look like little white birds." The old birds feed them with 

 larvae (often a long, green worm), large moths (after pulling off the 

 wings), and later, when the shrubs have fruited, with cornelberries. 



The young birds at this time, as well as the adults, give a curious 

 note which attracts our attention to these family gatherings. It 

 strongly suggests the distant clipping of garden shears — a sort of 

 sneeze. 



Audubon (1842) gives the incubation period as 12 days, and says 

 of the young birds : "On the sixteenth day after their exclusion from 

 the egg, they took to wing, and ascended the branches of the tree, 

 with surprising ease and firmness." 



Plumages. — [Author's note: Dr. D wight (1900) calls the natal 

 down "pale wood-brown" and describes the juvenal plumage as "above 

 wood-brown, very pale on pileum and nape, darker and faintly tinged 

 with olive on the back. * * * Below, white, the crissum tinged 

 with pale primrose-yellow. Auriculars, orbital ring and superciliary 

 line white." 



There is a partial postjuvenal molt, beginning early in August, 

 which involves the contour plumage, and the wing coverts, but not 

 the rest of the wings nor the tail. This produces a first winter plum- 

 age which is practically indistinguishable from the winter plumage 

 of the adult, greener above and more buffy white below than the previ- 

 ous plumage. 



Dr. Dwight says that the nuptial plumage is acquired by wear, but 

 Ned Dearborn (1907) found March and April specimens of the west- 

 ern race undergoing a scattered molt on the head and breast. This 

 may also be true of other vireos, though we have not the proper speci- 

 mens to show it.] 



Food. — In his study of food habits of the vireos, Dr. Edward A. 

 Chapin (1925), summarizing his findings, says: 



The economic status of the warbling vireo is in some ways more distinctly 

 unfavorable than that of the other species of this family of birds, especially 

 in its consumption of ladybirds. In more than a third of the stomachs exam- 

 ined the remains of these beneficial beetles were found. ♦ * * 



On the other hand, the injurious insects taken by the warbling vireo make 

 up the greater part of the food. Lepidopterous remains, including adult moths 

 and butterflies, caterpillars, pupae, and eggs, were taken from about 77 per 

 cent of those examined. This alone should atone for the bird's injurious pro- 

 clivities along other lines. * * * Little if any of the vegetable food taken 

 was obviously cultivated, in most cases being from plants not used for their 

 fruits. It seems reasonable, then, to class the bird as neither beneficial nor 

 injurious. 



