GAMBEL'S WHITE-CROWNED SPARROW 1331 



"August 26. At meadow between 8- and 9-mile, found only three 

 immatures. Heard no song. Saw no adults. I listened and looked 

 at spots where found Gambel's sparrows last week. None there. 

 Did not see any large migrating flocks anywhere this a.m. 



"August 27. At junction of railroad tracks and road to Nenana, 

 no Gambel's sparrows seen or heard. Saw one immature Gambel's 

 in meadow between 8- and 9-mile. Heard two Gambel's songs in 

 rapid succession. 



"August 30. Drove slowly along Chena Pump Road to North 

 Star Ranch. Stopped to look and listen. No birds of any species 

 except fox sparrows seen or heard. Stopped back of trap site 3 and 

 listened. Heard geese and a fox sparrow but no Gambel's sparrows." 



To fill in the details of the picture of fall activity in the Gambel's 

 sparrow at College, I operated 9 Potter traps at four stations around 

 a field near the territories of about 11 nesting pairs, banded and 

 released 256 adults and young, and collected specimens for analysis 

 of molt, fat, gonad size, thyroid activity, and body weight. The 

 data from banding and collecting during the period from June 26 to 

 August 27 substantiate the impression, given by the field notes on 

 behavior just quoted, that by early August migration was in full 

 swing. The local breeding birds probably left the trapping area 

 at least by late July, and from then on until late August successive 

 waves of Gambel's sparrows passed through the area, staying on the 

 average only a few days before moving on. 



The data reveal a major difference between fall departure at 

 College and spring departure at Davis and Santa Barbara: in the 

 north the residents at the trapping area left very early in the migra- 

 tion period, and were replaced by successive influxes of birds, pre- 

 sumably from farther north, whereas in the south the winter residents 

 gradually decreased in numbers until all had gone, and they were not 

 replaced by others. One similarity between spring and fall departure 

 has been noted: in both fall and spring, the birds may start their 

 migration before the molt is finished, and while still accumulating 

 fat. 



Mrs. Priscilla Phillips (personal communication) made daily 

 observations on the arrival of white-crowned sparrows at her home 

 in Hope Ranch for five consecutive years, from 1957 through 1961. 

 In addition, during the first three years she trapped and banded 399 

 Gambel's sparrows at her feeding station, where the combination of a 

 nearby lemon orchard, brushy hillsides, and a well-watered lawn 

 provided optimum conditions for attracting and observing the flocks, 

 some adults of which had doubtless fed there the previous winter. 



One point of particular interest is the near identity of dates for the 

 first white-crowned sparrow seen by Mrs. Phillips at Hope Ranch 



