THE GROUND SQUIRRELS OP CALIFORNIA. 



611 



short range. These "husking places" are conspicuously marked by 

 the hulls of seeds and by the rinds and pits of cultivated or wild fruits. 

 Examination of these "kitchen middens", will sometimes give a pretty 

 accurate idea of the character of the squirrels' rations in any locality. 

 A great many of the matured seeds, however, are carried directly below 

 ground to the permanent storehouse. 



Droppings, or feces, of the Ground Squirrel are to be observed widely 

 scattered rather than deposited in piles. They may be found about 

 the "husking places" or along the trails or paths which lead from the 

 burrow to the feeding grounds. In the burrows they are accumulated 

 in special places evidently set aside for the purpose. The feces are 

 generally of a cylindrical shape, rounded at the ends, but are quite 

 variable in diameter and volume. In April when green food is 

 abundant fresh feces are of a greenish hue and are often soft and 

 flattened. During the drier portions of the year the droppings are 

 covered with a dark brown coating, while the interior is composed of a 

 dry mass consisting of hulls of weed seeds and finely chopped and 

 shredded vegetable fiber, from 3 to 10 millimeters long. A typical dry 

 dropping measured 16 millimeters (f inch) in length, with a diameter 

 of 6 millimeters (i inch), and weighed -^q of a gram. 



The California Ground Squirrels do not dwell in thickly populated 

 "colonies" of sharply restricted extent, as is the case with the prairie 

 dogs of the Middle West. Still there is with our rodent a tendency to 

 occupy certain definite tracts in a general territory to the exclusion of 

 intervening places and this without obvious reason as regards food 



/-g /i' '6 /a ZO ZZ 2^ 26 Z8 30 



Fig. 6. Plot (plan and elevation) of used burrow of a male "digger" squirrel, as 

 excavated by J. Dixon on an alluvial talus in the foothills near San Emigdio, Kern 

 County, April 28, 1918. 



Main entrance at a ; refuse sump in old nest-cavity at & ; "blind" exit in thick grass 

 at c. Unusual depth of burrow, as shown in profile, was due to thick rock-filled over- 

 lying stratum, beneath which the squirrel had found easy digging horizontally after 

 having once penetrated the less resistant part of the layer at the edge of the talus. 



Total length of burrow, 34 feet; average diameter, 4i inches ; greatest depth reached, 

 5J feet ; volumetric contents of entire burrow, 4t cubic feet. 



