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



noted include all but those above 8500 feet altitude. Found com- 

 monly in the sagebrush association of Upper Sonoran and 

 Transition zones. 



The ranges of Oreoscoptes montanus and Artemisia tridentata 

 were practically coextensive. Where one thrives, there the other 

 apparently has its center of abundance. Thus, though the sage 

 thrasher was found in numbers on the desert about Quinn Kiver 

 Crossing, it was most abundant in the flats of Leonard Creek 

 where the sagebrush was flourishing. 



Habits. — The monotony of the desert quiet was often most 

 happily interrupted by the singing of this "mockingbird" of the 

 arid valley. The song is somewhat imitative, perhaps, as we 

 seemed to be able to recognize notes similar to those of the 

 meadowlark and of the black-headed grosbeak in it. 



Sage thrashers were rather frequently seen on a series of sage- 

 flats, ranging up to 8000 feet and above, near the head of Leonard 

 Creek. To a considerable extent the birds resemble the true 

 mockingbird (Mimus polyglottos leucopterus) as regards habits 

 of movement and song. When running along on the ground the 

 tail is held in much the same manner, and we noted that they 

 preferred running along on the ground to flying. The pose while 

 singing, and the manner of flight, also remind one of the mock- 

 ingbird. The differences between Oreoscoptes and Mimus seem 

 to have impressed Ridgway (1877, pp. 400, 401) to a greater 

 degree than the resemblances. It is true that in its habits it 

 clearly shows thrasher afSnities, and this, together with the fact 

 of its being sage-loving, makes sage thrasher by far the most 

 appropriate vernacular name. 



An individual of one pair which was observed on a high sage- 

 flat in the mountains lifted its wings at intervals while singing, 

 as Ridgway (1877, p. 400) has noted. These birds were seen at 

 an altitude of 8500 feet in a narrow depression along the side of 

 which was a snowbank. It seems remarkable that this bird, 

 ordinarily associated with wide expanses of desert, should be 

 found on a level with the summer snow in the mountains. 



The birds were often observed perching on rocks, in locali- 

 ties where boulders furnished one of the principal features of 

 the landscape. 



