MEADOW MICE 123 



Yosemite meadow mice, which cut pathways in the grassland. Of the latter 

 group the first two inhabit respectively the San Joaquin Valley and the 

 western foothills. The last, the subject of the present chapter, is distributed 

 over most of the high Sierras from the neighborhood of Yosemite Valley 

 eastward to the plateau country on the western side of Mono Lake, (See 



%. 19.) 



The local meadow mice are all much alike in general outward appearance 

 and so the Yosemite Meadow Mouse may be taken as an example for 

 detailed treatment. (See fig. 20&.) The nose is blunt, the eyes prominent 

 and bead-like though not so large in proportion to the head as those of 

 white-footed mice. The ear is rather short and therefore nearly or quite 

 buried in the copious fur. The body is rather chunky, the tail short and 

 slender, and both front and hind pairs of feet are inconspicuous. The 

 pelage of these mice is distinctive, being rather long, dense, and soft, and 

 of fluffy appearance. This type of pelage is found in various other animals 

 which like the meadow mice live about water where the pelage must per- 

 form the dual function of keeping the animals both dry and warm. 





Fig. 16. Tails of (a) Yosemite Meadow Mouse and (b) Sierra Cantankerous Meadow- 

 Mouse. Natural size. 



The Yosemite Meadow Mouse like the other path-cutting species has a 

 short tail, less than half, even but a third the length of the head and body ; 

 also the tail is of nearly uniform color. These features will usually serve 

 to distinguish any of the path-cutting species from the Cantankerous 

 Meadow Mouse. But within the first-named group there is no good external 

 character to separate the species. The distinctive features are found in 

 the skulls and hence can be determined only from museum specimens. 

 The Yosemite Meadow Mouse is generally more blackish, but old indi- 

 viduals have as much reddish coloration on the upper surface as does the 

 foothill and valley species {californicus). In the field, distribution is the 

 best clue for separating the short-tailed species. No specimen of yosemite 

 has been found below 3800 feet (the floor of Yosemite Valley), while 

 mariposae of the foothills penetrates the mountains no farther than Cas- 

 cades (3600 feet). 



