1278 U.S. NATIONAL MUSEUM BULLETIN 23 7 pabt 3 



Nesting. — Whereas Alfred O. Gross (1937) could write that "the 

 height of the breeding season of the White-crowned Sparrow on the 

 Labrador coast is during the first two weeks of July," for the Lab- 

 rador peninsula as a whole, most eggs are laid by mid-June. This 

 varies greatly from season to season, however, and from region to 

 region; the season in the higher southern third of the vast peninsula, 

 for example, is usually later than in the lower areas farther north. 



In mid-morning on June 16, 1957, I surprised a bird forming a 

 nest. It had pulled out mixed hairy-cap mosses and Cladonia lichens 

 for a proper cup in the shade of a dwarf birch. From a total of 

 some 30 nests examined in situ, it seems safe to consider my descrip- 

 tion (in Todd, 1963) as typical: "four inches in outside diameter and 

 two and five-eighths inches inside. The inside depth was one and 

 one-half inches. The main body of the nest is woven of fine grass 

 stems, the outside is made up of mixed moss stems, and the bottom 

 is lined with very fine root fibers, or in one case with white ptarmigan 

 body-feathers." Harrison F. Lewis (in litt.) once found a nest lined 

 with light gray hair, perhaps that of a dog. Most nests set into the 

 moss-lichen or lichen-crowberry mat are partly concealed by over- 

 hanging branches of dwarf birch or Labrador tea; not infrequently a 

 nest is neatly tucked into the lower side of a moss or crowberry 

 (Empetrum) mound. Much less frequently, nests are built into moss 

 hummocks on a string of heath shrubbery some distance out in a 

 sphagnum bog. Although I have never seen an elevated nest, 

 Arthur A. Allen wrote me that whereas all the nests he had found in 

 the Churchill region were on the ground, on the Labrador Coast 

 (North Shore) "the few nests I saw were in small firs." Earlier, 

 Oliver L. Austin, Jr. (1932) had quoted Moravian missionary Perrett's 

 notes from Makkovik, Labrador, concerning a nest "about three feet 

 from the ground in bushes thrown over a boat to protect it from 

 the sun." 



On June 30, 1957, I found an otherwise typical white-crown nest 

 in a "hybrid" habitat near the airport at Schefferville (Knob Lake), 

 Quebec, which contained 8 eggs and had 3 birds in attendance. On 

 July 2 the eggs and the two birds that came to incubate between 

 10:45 a.m. and 1:30 p.m. were collected by Don R. Oliver of the 

 McGill University Subarctic Laboratory and shipped to me at 

 Brown University, where William Montagna dissected them. Both 

 birds were females in comparable stages of gonadal regression, with 

 equally developed brood patches. One bird showed two clear follicles 

 and what appeared to be two coalesced follicles; the other had three 

 clear follicles and one questionable follicle. Although polygyny has 

 been reported in Emberizines before (e.g., corn bunting) this appears 



