1324 U.S. NATIONAL MUSEUM BULLETIN 23 7 ^aet 3 



to Gaviota Beach, Santa Barbara County. (Two breeding records 

 at Goleta Flat, Santa Barbara County.) 



Egg dates. — California: 215 records, March 3 to July 24; 112 records, 

 April 4 to April 27; 28 records, May 2 to May 15; 7 records, June 12 to 

 July 24. 



ZONOTRICHIA LEUCOPHRYS GAMBELII (Nuttall) 



GambeFs White-crowned Sparrow* 



PLATES 68 AND 69 



Contributed by Barbara Blanchard DeWolfe 



Habits 



The populations of Gambel's white-crowned sparrow discussed in 

 this section are those wintering at Davis, Calif., and those breeding 

 at Mountain Village and College, Alaska. As none of the thousands 

 of Gambel's sparrows banded on the wintering grounds has been 

 recaptured on the breeding grounds, we do not know where the birds 

 of a given wintering population breed or vice versa. 



Gambel's sparrows nesting in Alaska compress their breeding cycle 

 into an even shorter period than the Puget Sound sparrows at Friday 

 Harbor. They establish territories, nest, and care for the single 

 brood of young until they become independent in about 2% months. 

 The greater part of the time saved lies in the fledging of only one brood, 

 but compression of several other intervals is necessary to make fullest 

 use of the short time between arrival on the breeding grounds and 

 gonad regression. Males arrive first and in almost full breeding 

 condition. They immediately establish their territories, so that no 

 time is lost after the females arrive either in achieving physiological 

 readiness to mate or in finding and defending nesting areas. The 

 females are ready to mate and to begin work on the nest within a few 

 days. The interval between completion of the nest and laying the 

 first egg also averages shorter than in pugetensis. 



Spring. — In spring the members of flocks wintering at Davis showed 

 some slight hostility toward one another about 10 days before the 

 first individuals departed. They squabbled over food and, less 

 frequently, fought or pursued one another. Otherwise the behavior 

 prior to migration was identical to that described for the Puget 

 Sound sparrow. In 1943 the Gambel's sparrow flocks at Davis 

 began to decrease in numbers on April 13, the last banded bird was 

 seen April 20, the last unhanded one on April 30. 



*Additional material on this race is included in the account of Nuttall's white- 

 crowned sparrow, pp. 1292-1324. 



