PHILADELPHIA VIREO 355 



adelphia Vireos take to their young consisted largely of naked cater- 

 pillars, brown, green, and whitish, and of flying insects of various 

 kinds." 



For two or three days before the last nestling finally left the nest 

 the young birds were more or less restless and frequently hopped about 

 in the tree or fluttered down to the ground, or even made short flights. 

 They were often rescued from the ground and placed in the tree or 

 returned to the nest. At such times the parents were quite excited and 

 aggressive ; Dr. Lewis says : "I climbed the tree again and, as I drew 

 near the youngster, one of the parents dashed at me, crest erect, scolding 

 loudly and rapidly. This was continued until I left the tree and was 

 the first scolding I had received from an old bird when I was in the 

 tree." 



Dr. D wight (1897) writes: 



It is evident that but one brood is raised in a season. I have seen young 

 birds as early as July 7, comical little chaps largely bare skin and the promise 

 of a taiL At this tender age they are unwilling to essay flight except when urged 

 by anxious parents to make a clumsy, flying leap from one twig to another, but 

 they are knowing enough to keep quiet when they hear a crashing in the bushes, 

 and as they become older they lose no time in moving quickly away. I have 

 found them in alder thickets or along some of the bushy cattle paths which end 

 abruptly at steep walls of rock or lose themselves in small clearijigs. In fact I 

 never could tell when or where I might run across the birds, young or old, but dur- 

 ing the latter part of July, when the moult is in progress, it is almost impossible 

 to find them anywhere. 



Plumages. — Dr. D wight (1900) describes the natal down as "pale 

 drab-gray." And he says that the juvenal plumage is "similar to F. 

 olivaceus and F. gilvus, but darker above and distinctly yellow below. 

 Above, wood-brown, darker and olive tinged on the back and wing 

 coverts. Wings and tail clove-brown with olive-green edgings. Below 

 primrose-yellow, auriculars, orbital ring, and superciliary stripe buff- 

 yellow. Lores and postocular streak dusky." 



An incomplete post juvenal molt, involving the contour plumage and 

 the wing coverts, but not the rest of the wings or the tail, begins at 

 the end of July This produces a first- winter plumage, which is prac- 

 tically indistinguishable from the winter plumage of the adult. Dr. 

 Dwight describes this as "similar to the previous plumage but greener 

 with a grayer crown, and brighter yellow below. Above, dull olive- 

 green, slate-gray on the pileum. Below pale canary -yellow, whiter on 

 middle of abdomen. Sides of head pale greenish or grayish buff, 

 superciliary stripe paler; transocular streak dusky." He says that 

 the adult, at this season, is usually paler yellow below with a larger 

 area of white on the abdomen. 



There is apparently no prenuptial molt, but specimens taken at the 

 proper season to show it are not available. The sexes are practically 

 alike in all plumages. 



