60 University of California PiiMi cations in Zoology [Vol. 21 



were not startled by it; but at first they all started at the strange 

 noise. In each case the lens used was of the same focal length, six 

 and one-half inches, and was placed approximateh' thirty inches from 

 the animal, which was then photographed while sitting or standing 

 at attention under natural conditions. Under these conditions %o 

 second exposure stopped motion in an alpine chipmunk {Eutaiuins 

 alpinus) ; ^'25 of ^ second exposure sufficed for California pocket 

 gopher {Thomomys hottae), Great Basin pocket mouse {Perognathus 

 parvus olivaceus), Tahoe chipmunk {Eutamias speciosus f rater), and 

 Nelson antelope ground squirrel {Ammospenyiophilus nelsoni), and 

 Yio of a second was successful in the case of the California ground 

 squirrel {Citelhis deecheyi). 



When trapped, bushy-tailed wood rats have proved much fiercer 

 as well as stronger than round-tailed wood rats. They fight vigorously 

 when cornered. At such times, when closely pressed, they have been 

 known to utter a shrill, angry squeal, but only under such circum- 

 stances have I ever personally known this animal to utter a sound. 



TEACKS AND OTHER SIGN 



Tracks are usually difficult to find even where the animals are 

 comparatively common, since the ground ordinarily inhabited by them 

 is so rocky that there is no dusty soil suitable to receive such impres- 

 sions. Faeces are perhaps the sign of the animal most commonly met 

 with. These are usually found scattered about or in groups of three 

 or four in certain selected niches or on level places among the granite 

 boulders among which the animals dwell. (See pi. 2, fig. 3.) 



At certain points, usually at or near some prominent lookout 

 station, peculiar dull white or yellow patches or streaks a foot or 

 more in length are sometimes to be observed on the gray granite 

 boulders. Such spots mark the place where liquid excrement is 

 regularly deposited. Near Jackass Spring, in the Panamint Moun- 

 tains, Inyo County, October 4 to 8, 1917, one male and three female 

 Teanoma were taken in unbaited rat traps set on the top of a granite 

 boulder beside one of these yellow spots. From the regularity with 

 which the wood rats were taken at this point it seems certain that 

 such places were visited nightly and that they possibly seiwe as 

 "intelligence bureaus," such as are commonly established on promi- 

 nent ridges by coyotes. 



