300 University of California Publications in Zoology [Vol. 16 



Columbia Basin Sagebrush Faunal Area and Fauna 



Habitats and Associations: 



Sagebrush. Water-margin. 



Roelcy-slope. Aquatic. 



Willow. Aerial. 



The Columbia Basin sagebrush area is charactei'ized by the 

 dominance of the sagebrush habitat. This is found well developed in 

 the western end of Walla Walla County near the Columbia and Snake 

 rivers. Sagebrush extends up the valley of the Walla Walla River to 

 the neighborhood of the town of Touchet or a little above this. It 

 also extends up Snake River for some distance, but the exact limits 

 are not known. Sagebrush is not dominant south of the Snake River 

 at Lyon's Ferry, so the sagebrush area does not extend eastward that 

 far. Between the Walla Walla and Snake rivers the sagebrush area 

 extends eastward a number of miles, but as the land rises the sagebrush 

 gradually gives place to the prairie. The change is very gradual and 

 no abrupt line of demarcation can be drawn. The typical sagebrush 

 area probably does not extend eastward from the Columbia River more 

 than about ten miles. 



There are some rocky slopes in all the higher hills of the sagebrush 

 area and along the streams there are numerous basaltic bluffs. Along 

 the Walla Walla River there is a narrow growth of willows, but along 

 the Columbia and Snake rivers in western Walla Walla County there 

 are almost no trees, and brush is developed in only a few places, so 

 that along these streams the willow habitat appears only in isolated 

 patches. 



CHARACTERI.STIC SPECrE.S OF THE COLUMBIA BaSIN SAGEBRUSH FAUNA 



Scaphiopus hammondii hammomlii. Lanius ludovicianiis excubitorides. 



Seelopoius graeiosus. Onyehomys leueogaster fiiscogriseus. 



Phrynosoma douglassii douglassii. Perognathus parvus parvus. 



Centroeercus urophasianus. Perognathus lordi eolumbianus. 



Ampliispiza nevadensis nevadensis. Perodipus ordii eolumbianus. 



The Columbia Basin sagebrush fauna is characterized by the 

 presence of a considerable number of species nearly all of which are 

 specially adapted to semi-desert conditions and are inhabitants of the 

 sagebrush habitat. 



