122 University of California Publications in Zoology [Vol.30 



May 31, containing two eggs ; on June 4 it held a set of four. Other 

 nests were found on June 11, with four eggs (no. 1983), and on 

 June 12, with five eggs (no. 1984). These were all essentially alike 

 in structure and location. They were on the ground in rather damp 

 meadow land, in fairly open areas interspersed with thickets of willow 

 and dotted with tiny wild rose plants. The nests were well hidden 

 under tufts of grass, willow shoots, or roses. 



One (no. 1983) measures 120 mm. outside diameter, 65 mm. inside 

 diameter, 40 inm. inside depth. The outer walls are mostly shreds of 

 bark and coarse (dry) grass stems, the lining is of fine grass and a 

 little horse hair. 



Another nest (no. 1984) measures 110 mm. outside diameter, 

 65 mm. inside diameter, 35 mm. inside depth. The outer walls are 

 mostly shreds of bark, the lining is of fine grass and a little mammal 

 hair, mostly dog and mountain sheep (taken from a nearby carcass of 

 the first, and scraps of hide of the second). 



On June 25 the first young birds appeared, but although the 

 species was common, relatively few spotted young were seen at any 

 time. The birds nested in fair abundance in gardens in the town of 

 Atlin, and in waste land between the houses, and more young birds 

 were seen there than elsewhere. On July 11 the first juvenile was 

 collected showing beginnings of the post-juvenal molt, which, roughly, 

 continues through the month of July. On August 6 a young male was 

 taken, still with many pinfeathers but with none of the juvenal 

 plumage left. By August 14 the young birds were practically through 

 the post-juvenal molt. Adults at that date were nearly all stubby- 

 tailed. A young female collected August 24 is in perfect first winter 

 plumage. 



During the breeding season the Gambel sparrow was confined to 

 the lowlands, but soon after the beginning of the post-juvenal molt 

 there was a scattering of old and young that took many individuals 

 high up into the mountains. There they formed loosely connected 

 flocks in company with the golden-crowns, the beginning of an 

 association that in California we see carried on throughout the winter. 



On August 29 the species was still abundant. It was last noted on 

 September 5, but as a number of the birds were seen on that date, some 

 probably lingered several days longer. Careful search on September 

 19, however, failed to disclose a single one. 



Sixteen specimens were collected (nos. 44806-44821), fourteen in 

 Juvenal plumage or in various stages of the post-juvenal molt, and 

 two in first winter plumage. 



