396 University of California Publications in Zoology. [Vol. 7 



These two individuals were the only representatives of the 

 genus Junco seen. As the flight feathers are fully formed in the 

 specimen just mentioned there is, of course, a possibility that 

 the young birds were able to traverse the deserts between the 

 Warner Mountains of California, where the species is common, 

 and the Pine Forest Mountains of Nevada. The distance is 

 approximately eighty-five miles and there are several low desert 

 ranges, reaching a height of 6000 or 7000 feet, interrupting the 

 continuity of the plain between, with intervening flats or hollows 

 which average about 4800 feet altitude. It seems probable that 

 full-grown young birds could have made the trip, and to regard 

 this as a breeding record would seem to be unjustified. 



Amphispiza bilineata deserticola Ridgway 

 Desert Sparrow 



Distribution. — Less common than the sage and Brewer spar- 

 rows, but still not rare. Noted at Quinn River Crossing, Big 

 Creek Ranch, Alder Creek Ranch, and Virgin Valley. None 

 were observed above 5000 feet. Northern Nevada is, in all prob- 

 ability, about the northern limit of the range of the species. 



The birds were more numerous along the foothills in the 

 vicinity of Big Creek Ranch than at any other locality. A single 

 bird was noted in the low brush on a flat-topped and very arid 

 ridge near Alder Creek Ranch. 



Habits. — This bird, which was found only in the sagebrush 

 association, resembles the sage and Brewer sparrows in habits. 

 Its Thryomanes-like song could be heard at intervals, and as the 

 bird perched on the topmost twig of a bush its black throat 

 rendered it conspicuous for a considerable distance. 



Individuals were often difficult of approach, as they would 

 run along the ground until out of firing range, taking advantage 

 of the cover afforded by the sagebrush, and flying twenty or 

 thirty yards ahead when hard pressed. 



Prom the general similarity of the habits of the desert and 

 sage sparrows, it might be expected that competition between 

 them, at least of a subtle sort, would be rather severe. Appar- 

 ently the interests of individuals conflict in more evident ways, 

 as a desert sparrow was on at least one occasion seen fighting 

 with a sage sparrow. 



