1286 U.S. NATIONAL MUSEUM BULLETIN 237 part 3 



At Buckeye Lake, Ohio, Milton B. Trautman (1940) records first 

 arrival as October 1 to 8, with the peak of migration October 10 to 27, 

 and the last departure November 3. White-crowns first wintered 

 there in 1953. The ratio of immatures to adults, M. B. Trautman 

 reports, was usually 2 to 1, though in some years there were 97 im- 

 matures to 3 adults. As earlier mentioned, on Block Island, 10 miles 

 off the Rhode Island shore, immature birds are almost or quite alone, 

 which suggests that adults are too experienced to allow themselves to 

 be wind-drifted out to sea during migration. Robert A. Norris (1954) 

 reports a wintering flock of 30 immatures to 1 adult in Georgia; he 

 considered the sex ratio balanced. 



Concerning autumn habitats, Milton B. Trautman (1940) writes, 

 "As in spring, the birds were found in brushy situations, but many 

 were also present in dense patches of high weeds, and in weedy uncut 

 cornfields. Autumn sparrows were somewhat more secretive than 

 were spring birds, and it was only by remaining quiet in a dense weed 

 patch or brushy thicket and giving a Screech Owl whistle that a true 

 indication of numbers could be obtained." 



Robert A. Norris (1954) writes that white-crowns do not flock with 

 other species and that on the Georgia wintering grounds he studied, 

 the birds are "found in more open country with less cover and also 

 farther from water than is typically the case with White-throated 

 Sparrows." The March-April weights of his Georgia birds ranged 

 from 23.7 grams for the smallest female to 31.2 grams for the largest 

 male, the 13-bird sample averaging 30.05 grams. In a larger 

 sample, however, Paul A. Stewart (1937) found that 21 adults ranged 

 from 19.9 to 37.1 grams, with a mean of 31.26 grams; 31 immature 

 birds ranged from 23.5 to 32 grams, with a mean of 27.56 grams. 



Cortopassi and Mewaldt's (1965) plot of the distribution of this 

 species from the Christmas Bird Counts of Audubon Field Notes shows 

 that the wintering population has two centers of concentration, one 

 in western Texas and southeastern New Mexico and the other in the 

 Appalachian plateau and its western extension, the interior low pla- 

 teaus and Ozark plateaus. In these two broad belts the bird-watcher 

 may expect to see from 1 to 10 birds per hour afield during a full day's 

 quest. They warn, however, that the Texas-New Mexico area of 

 concentration may be the result of the oasis-like nature of suitable 

 habitat, and the special attention this receives from the bird-counters. 

 According to their analysis of banded bird data, only the eastern race 

 of the white-crown is regular east of the 90° parallel. Between 90° 

 and 105° (the Great Plains region) the eastern and GambeFs races 

 migrate and winter together. Intergrades from the west side of 

 Hudson Bay winter mostly in the Dakotas. 



