400 BULLETIN 2 3, UNITED STATES NATIONAL MUSEUM 



of the specimens. An adult taken July 26 also is molting, tlie yellowish-green 

 forming a patch on each side of the breast. Took specimens in the transition 

 from the breeding to the autumnal plumage near Lake St. Croix, August 14, 

 when the species was abundant. 



An immature female blackpoll that I collected on the mainland west 

 of Nain, Labrador, on August 12, 1934, represents a transitional state 

 between the juvenal and first winter plumage, with feathers of each 

 plumage about equally represented. Another specimen, a male taken 

 near the same place on August 18, 1937, has its winter plumage prac- 

 tically completed. At Lost Kiver, in the White Mountains of New 

 Hampshire, I have seen young in various stages of transition from 

 the juvenal to the first winter plumage during the last week of July. 



Alexander Wetmore (1936), who has made counts of the number 

 of contour feathers of passeriform and related birds, found that a 

 male blackpoll weighing 17.6 grams, taken October 15, 1933, had 1,583 

 contour feathers with a total weight of 1.2 grams. 



S. P. Baldwin and S. C. Kendeigh (1938) have made the following 

 weighings of black-polled warblers: 1 adult taken in May, 12.4 gm,; 

 3 males taken in September average 11.4 gm. ; 1 female taken in Sep- 

 tember, 12.8 gm. ; 3 immature birds taken in September average 11.5 

 gm. ; and 4 in October average 13.9 gm. 



Albinistic plumages of the black-polled warbler apparently are not 

 rare. J. Harris Reed (1888) describes the plumage of a male taken 

 May 12, 1888, at Upper Chichester, Delaware County, Pa., as follows: 



The entire crown, with the exception of three or four small black feathers 

 over the eyes, is pure white, the edges of the feathers tipped with cream color 

 which is more decided fringing the neck. The upper tail-coverts and rump 

 are pure white, extending high up on the back and passing irregularly through 

 the interscapulars and joining the white on back of neck and crown ; rather silky 

 across the rump. The interscapulars form an irregular bar across the shoulders. 

 The scapulars and tertiaries are sparsely spotted with white, most prominent 

 on the right side. The sides of breast are streaked as usual, although of a 

 rusty color, rather obsolete as they approach the chin which is pure white. The 

 throat and breast are ochroleucous. Otherwise the plumage is natural. * * * 

 The white feathers are immaculate from the quills out, none being edged or 

 spotted with the natural colors. 



Charles H. Townsend (1883) states that a black-polled warbler in 

 the Academy of Natural Sciences of Philadelj^hia has the entire 

 plumage suffused with white, and William Dutcher (1888) found a 

 perfect albino blackpoll killed by striking Fire Island light on Sep- 

 tember 23, 1887. Other cases of pure and partial albinism have been 

 reported, indicating that this abnormality may be expected. 



Food. — Anyone who has observed the blackpolls during migration 

 and especially in their nesting haunts in the coniferous forests is well 

 aware of their insect-feeding habits. Not only do they glean the 

 leaves and twigs of insects and their larvae, but frequently they dart 



