DISTEIBUTIOX OF THE 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 discu>ssion 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, 36a, and figure 21.) 



ASSOCIATIONS WITHIN THE LOWER SONOEAN ZONE 

 Open-water (two t}-pes. River and Rose-thicket 



Slough) A'alley-oak 



Riparian (Willow-cottonwood) Hog-wallow prairie 



Marsh Rock outcrop 



Meadow 



ASSOCIATIONS WITHIN THE UPPER SONOEAN ZONE 



Stream Digger-pine 



Riparian (Willow) Blue-oak 



Meadow Dry grassland 



Live-oak Rocky-slope 

 Chaparral (two types, Adenostoma 

 and Ceanothus cuneatus) 



ASSOCIATIONS WITHIN THE TRANSITION ZONE 



Swift -stream Black -oak 

 Riparian (two types. Willow-cotton- Golden-oak 



wood and Alder) Yellow-pine 



Meadow Silver-fir 



Dry grassland Boulder-talus 



Chaparral (two types, Sticky-man- Cliff 



zanita and Buckthorn) 



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

 GREAT BASIN FAUNAE DIVISION OF THE TRANSITION ZONE 

 Alkali-lake Sagebrush 



Riparian (Willow) Pifion-juniper 



Rose-thicket Cercocarpus 



Shepherdia 



