DISTRIBUTION OF TEE ANIMALS 11 



As is clearly set forth in some of the literature we here cite for perusal 

 by the inquiring reader, the limitation of species on the basis of the life- 

 zone concept is not the only sort of segregation which occurs. Indeed, 

 locally, as in Yosemite Valley proper, often a far more conspicuous manner 

 of delimitation is manifest, the delimitation which takes place on the 

 basis of 'associations.' These minor units involve each a certain type of 

 environment within one zone ; furthermore, closely similar or even identical 

 associations may recur, or be continuous, in two or more adjacent zones. 

 Not rarely, associational restriction seems to be transcendent over zonal 

 restriction, as in the case of the badger, western chipping sparrow, and 

 rock wren. Appropriate discussion of these cases will be found in the 

 chapters (pp. 92, 452, 550) treating of these species. 



Some of the more important associations of animal with plant or sub- 

 stratum conditions that it has proved useful to recognize in the Yosemite 

 section are as follows, classified by zones. The names chosen are those of 

 some predominating feature, usually of the vegetation. (Consult plates 13 

 to 19, 36o, and figure 21.) 



ASSOCIATIONS WITHIN THE LOWEE SONOEAN ZONE 



Open-water (two types, Eiver and Eose-thicket 



Slough) Valley-oak 



Eiparian (Willow-cottonwood) Hog-wallow prairie 



Marsh Eock outcrop 

 Meadow 



ASSOCIATIONS WITHIN THE UPPEE SONOEAN ZONE 



Stream Digger-pine 



Eiparian (Willow) Blue-oak 



Meadow Dry grassland 



Live-oak Eocky-slope 

 Chaparral (two types, Adenostoma 

 and Ceanothus cuneatus) 



ASSOCIATIONS WITHIN THE TEANSITION ZONE 



Swift-stream Black-oak 



Eiparian (two types, Willow-cotton- Golden-oak 



wood and Alder) Yellow-pine 



Meadow Silver-fir 



Dry grassland Boulder-talus 



Chaparral (two tj^es, Sticky-man- Cliff 



zanita and Buckthorn) 



ASSOCIATIONS ON THE AEID EAST SIDE OF THE SIEEEA, IN THE 

 GEEAT BASIN FAUNAE DIVISION OF THE TEANSITION ZONE 



Alkali-lake Sagebrush 



Eiparian (Willow) Pinon-juniper 



Eose-thicket Cercocarpus 

 Shepherdia 



