PUGET SOUND WHITE-CROWNED SPARROW 1349 



clutches, 4 had four eggs each and 3 had five eggs. The average 

 was 4.4. A single third clutch had five eggs. 



Clutch size varies with latitude in pugetensis. 32 clutches collected 

 at latitude 41 °N. average 3.56 eggs per clutch, whereas 48 clutches 

 taken at latitude 49 °N. average 4.04 eggs per clutch. 



Incubation. — The start of incubation in relation to egg laying shows 

 about the same variation as in nuttalli. The length of the incubation 

 period is the same, and the eggs of any one set show about the same 

 variability in hatching time as do those of nuttalli. I marked the eggs 

 of three sets at Friday Harbor. They did not hatch in the order 

 laid. One set of three hatched in the sequence 2, 1,3, another 3, 2, 

 1, and a set of four in the order 2, 1, 3, 4. 



Young. — The behavior of the parents up to the time the young 

 leave the nest is identical with that of Nuttall's. For about the 

 first week after the young are fledged the female alternates between 

 feeding them and building the second nest. Thereafter the male 

 takes over all care of the fledglings. On an average of 11 days after 

 one brood has been fledged, the female has begun to sit on her second 

 clutch. The male then performs the duties of feeding the fledglings 

 and guarding the territory and the second nest. He makes short 

 excursions with his young outside the territory, but never for more 

 than a few minutes at a time. Once I found three males from contig- 

 uous areas foraging with their young in the same 50-yard-square 

 raspberry patch. None appeared to resent the presence of the others. 



As the time for the hatching of the second brood drew near, the 

 males spent more and more time near the nest and less in feeding 

 and watching the fledglings. The young birds left their parents' 

 territories at an earlier age than did the young Nuttall's. One young 

 bird was found alone across the border from its parents' territory 

 when only 25 days old. Out of seven broods that I watched almost 

 daily, the oldest fledgling fed by the male was 27 days old. 



Owing to the compression of several phases of the c} r cle, partic- 

 ularly of the interval between broods, the Puget Sound sparrows, 

 although they began to breed more than 6 weeks later than the 

 Nuttall's, had time to raise three broods before the regression of 

 the testes in late July. Unfortunately I was obliged to leave Friday 

 Harbor before recording the fledging of the third brood. Two females 

 that had fledged two broods each were sitting on their third clutches 

 when I left. All but 2 of the remaining 11 pairs of the group I watched 

 would have had ample time for a third brood before gonad regression 

 as recorded at other stations of like latitude. The general average 

 of success with the broods was not high. Before I left, only 3 out 

 of 13 pairs raised two broods successfully, whereas each of the remain- 



