VERTEBRATE FAUNA OF THE PACIFIC COAST 

 Anna hummingbird, and California bush-tit. Indus- 

 trious trapping would disclose characteristic species 

 of gophers, wood-rats, chipmunks, and mice of vari- 

 ous genera. The Upper Sonoran zone continues for 

 fifty miles until El Portal is reached where, on cer- 

 tain warm sun-facing slopes, it extends up to an 

 elevation of over 4000 feet. 



At the same point, El Portal, 2000 feet altitude, 

 on cool, north-facing slopes, the visitor for the first 

 time encounters the Transition zone, characterized 

 conspicuously by yellow pine, incense cedar, black 

 oak, and certain kinds of deer-brush (Ceanothus). 

 Proceeding by stage into Yosemite Valley the nat- 

 uralist finds this zone represented continuously 

 throughout the floor of the Valley and up to about 

 6000 feet altitude around its walls. Very few typic- 

 ally Upper Sonoran animals extend their ranges so 

 far as the floor of the Valley. Instead, one encoun- 

 ters the blue-fronted jay, robin, western bluebird, 

 junco or snowbird, and woodpeckers of several 

 species, notably one with a white head. 



If the tourist be of hardy frame and ambitious 

 nature he will want to push on east by trail to the 

 top of the great Sierran crest. In so doing he will 

 traverse the remaining three life zones. Upon 

 emerging by way of, say, the Tenaya trail upon the 

 rim of the Valley he will enter forests of silver and 

 red fir and lodgepole pine, these trees in company 

 characterizing the Canadian zone. Here he will 

 find bird life more plentiful than in the Yosemite 

 Valley below, and many new kinds will make them- 

 selves known by sight or sound. Restless droves of 

 golden-crowned kinglets and mountain chickadees 

 enliven the tree tops far overhead; nuthatches of 

 three species call incessantly; the curious Clarke 

 nutcracker shows obvious interest in the wayfarer, 

 for he expects to find forage about the camping 

 places; and sapsuckers of two species add to the 

 census of woodpeckers. These are only a few 

 among the many birds of the Canadian zone, while 

 mammals are likewise plentiful and include char- 

 acteristic species of chipmunks, gophers, red squir- 

 rels or chickarees, porcupines, bushy-tailed wood- 

 rats, and many kinds of mice and shrews. 



The Hudsonian zone is the belt of forest just 

 below timberline, and in it are encountered such 

 trees as the Alpine hemlock and white-bark pine, 

 together with several mammals and birds more or 

 less restricted to it. Above timberline, at about 

 10,000 feet altitude and for some one or two thou- 

 sand feet farther, plant life of dwarfed types con- 

 tinues, and here the rosy finch and the rabbit-like 



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