LECONTE'S THRASHER 413 



rocky hills or low mountains and on the south by the then snow-capped 

 San Bernardino Mountains. The floor of the desert was dry and hot, 

 sparsely covered with a scattered growth of creosote bushes, so widely 

 separated that we could easily drive anywhere among them on the 

 hard, sandy floor and so scantily branched as to afford a minimum of 

 shade beneath them. A few stunted mesquites relieved the monotony, 

 and there were scattered clumps or more often individual bushes of 

 chollas ( Opuntia echinocarpa^ the branching cholla, Opimtia higelovii, 

 the white cholla, or Opuntia ramocissima, the long-spined species) . As 

 we wended our way in and out among the scattered desert vegetation, 

 we frequently saw these sandy-colored thrashers running rapidly 

 ahead of us or dodging in low flight among and under the creosote 

 bushes. 



There are two northward extensions of the breeding range of Le- 

 Conte's thrasher in California, in Owens Valley and in the San Joa- 

 quin Valley, where the surrounding mountain ranges shut off hot and 

 arid valleys. While driving from Bakersville to the Kettleman Hills, 

 through Kern County, we saw a number of LeConte's thrashers on 

 the arid, sagebrush plains and noted some of their old nests in these 

 bushes ; my host, J. R. Pemberton, told me that they nest regularly in 

 the sagebushes in this region. 



Of the haunts of this thrasher in the San Joaquin Valley, Dr. Joseph 

 Grinnell (1933) writes: 



The most conspicuous element in the perennial vegetation about was a 

 species of salt-bush. Fragments saved have been identified for me by Dr. H. F, 

 Copeland, of the Herbarium, University of California, as Atriplex polycarpa. 

 * * * The bushes of it grow small and far-scattered on exposed, high terrain ; 

 but in low places, in ravines and along gullies, washes, or arroyos the bushes grow 

 eight or ten feet in diameter, and five feet or more high, and may crowd together 

 here or there along a favorable draw to form a continuous thicket. It is the 

 presence of this more luxuriant growth of atriplex that, together with much 

 open ground between the scattering bushes nearby, and the general climatic 

 conditions of high temperature and low humidity, appears to form the final 

 requirement controlling the presence and relative numbers of the LeConte 

 Thrashers in the San Joaquin Valley." 



Nesting. — The nests that we saw in the Mojave Desert were all 

 alike and similarly placed in the chollas (Optmtia echinocarpa, O. 

 higelovii^ or O. ramoGissimu) . The birds seemed to select the densest, 

 most thickly branched chollas, where the nests could be located but not 

 easily seen; in many cases it was necessary to chop away several 

 branches before the nest could be clearly seen, or even before the hand 

 could be safely inserted among the many bristling spines (see pi. 81) . 

 The nests were very bulky, often filling a large central space among 

 the sprawling branches, to which they were insecurely attached but 

 safely supported and guarded. The bulk of the nest consisted of a 

 great mass of thorny twigs and sticks, filling most of the space, on which 



