262 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



in a nest on July 25, 1912, and now in the Thayer collection, is 

 completely covered with long, soft down, "dusky drab*' to "blackish 

 brown" ; the down is longest on the back and rump and shortest on 

 the head ; the wing coverts are growing, and the primaries have burst 

 their sheaths for over a quarter of an inch. 



Frank M. Drew (1882) estimates that four years are necessary for 

 the black swift to acquire its fully adult plumage, wdiich hardly 

 seems likely. Based on a study of ten specimens, collected in Colo- 

 rado, he describes the succession of plumages as follows : 



A young male of the year, taken Sept. 17, was marked as follows. General 

 color dull black, every feather tipped with white, scarcely appreciable on upper 

 back and throat, broader on upper tail coverts and rump. Crissum almost 

 pure white. In birds of the second year the general plumage has a brownish 

 cast ; feathers of back tipped with brown, the head whitish, belly feathers yet 

 broadly tipped with white. The third year the color is black, with a very faint 

 edging of white on under tail coverts. In the fourth year pure black, fore- 

 head hoary, neck with a brownish wash. 



Tail in young of first year, rounded; in second year, slightly rounded; in 

 third year slightly emarginate, feathers becoming more acute. In adult, 

 forked, outer feathers three-eighths of an inch longer than inner. 



I have never seen a young black swift, with "every feather tipped 

 with w^hite," but I am inclined to believe that Mr. DreAv is correct 

 in describing this as the juvenal plumage. The juvenal plumage 

 apparently has never been described in the manuals, and probably 

 there are no specimens in young juvenal plumage in collections. The 

 downy young, described above, has the incoming feathers of the wing 

 coverts, and the remiges tipped with white. Enid Michael (1933) 

 had a young black swift brought to her on August 10, 1932, that had 

 fallen out of a nest and was unable to fly ; from what she had pre- 

 viously learned from her study of young swifts in their nests, she 

 estimated that this bird was about five weeks old; and she says: 

 "Every feather on its back, tail, wings and crown was daintily tipped 

 with white. The tiny feathers of its crown and forehead, being 

 fringed with white, gave its crown, and especially its forehead, a 

 frosted appearance." Mr. Kathbun has sent me the following de- 

 scription of a young black swift picked up dead in the Willamette 

 Valley, Oreg., September 20, 1924: "Seemingly an immature bird — 

 not in good condition of preservation. Back and abdominal feathers 

 tipped with grayish white. Head from bill to crown also with 

 grayish-white-tipped feathers. Primary wing feathers edged in 

 grayish white. Length 7 inches." From the above descriptions, and 

 from what shows in the few published photographs of the young 

 swifts in the nests, it seems fair to assume that the ju.venal or first 

 plumage is characterized by the white tips of the body plumage, above 

 and below, and by the white-tipped primaries. How long this plum- 



