1^4 Merriam, The LeCoiite Thvasher. \u-^. 



THE LECONTE THRASHER, HARPORHYNCHUS 

 LECONTEI. 



BY DR. C. HART MERRIAM. 

 Plate I. 



The great Colorado River, emerging from the marvellous 

 canons of northern Arizona, bends southward to traverse a vast, 

 inhospitable desert, parts of which, below the level of the sea, 

 surpass the deserts of India, Arabia, and even the great Sahara in 

 heat, aridity and desolation. The burning sun, set in a cloudless 

 sky, beats down relentlessly on a dreary expanse of sand, gravel 

 and clay, broken only by the seared walls of barren desert ranges. 

 The picture is made more weird and the way fraught with greater 

 danger by the mirage-breeding alkali beds that warn the experienced 

 traveller of impending danger ; but hundreds of venturesome 

 explorers, pushing on until crazed with thirst, have been overtaken 

 by despair and death. 



These deserts receive little water : the rainfall is meagre, the 

 streams from the surrounding mountains soon disappear in the 

 hot sands, and the broad Colorado itself hurries on to the sea as 

 if in a conduit, without imparting verdure to even its immediate 

 banks save in a few favored spots. The vegetation is scanty and 

 peculiar : the sandy gravel slopes are covered with the resinous 

 Larrea or creosote bush, more or less mixed with cactuses, yuccas, 

 daleas, ephedras and other desert forms, while the alkaline and 

 saline clay soils are dotted here and there with greasewoods and 

 fleshy saline plants. 



Such is the home of the LeConte Thrasher. The environment 

 is uncongenial to most diurnal forms of animal life, and the 

 usually dominant element of competition is nearly absent in the 

 struggle for existence — the struggle being one against hostile 

 conditions, not against a multitude of competitors. Diurnal 

 mammals are rare and restricted to a few species ; birds are 

 scarce, both as species and individuals, but reptiles are more 

 plentiful, particularly lizards and rattlesnakes. 



The area covered by these deserts is so large that different 

 parts have received different names, as the Colorado, Mohave, 



