THE GROUND SQUIRRELS OF CALIFORNIA. 



625 



Valley a ground squirrel was seen gathering green fruits from the top 

 of a four-foot manzanita bush. 



C. H. Merriam reports (1910, p. 5) that the seeds of the manroot 

 (Echinocystis fabacea) are eaten in the vicinity of Modesto from the 

 middle of May to the middle of December. The seeds are eaten from 



Fig. 13. Drawings from dissections to show relative extent 

 of cheek-pouches in (a) California Ground Squirrel and (b) 

 Belding Ground Squirrel. One cheek-pouch opens into the 

 mouth cavity on each side ; it is lined with membrane contin- 

 uous with that lining the mouth and is used for carrying food 

 materials such as seeds and bulbs from the forage ground to 

 either the store house or the husking place. It is to be inferred 

 that the California Ground Squirrel is much more of a seed- 

 gatherer than the Belding. The latter, like the Oregon Ground 

 Squirrel, is more of a grass-eater, and also does not garner 

 food to the extent that the "digger" squirrels do. 



the time they begin to form until they are fully ripe. "Other favorite 

 seeds are those of elderberry (Sambucus) , jimson weed (Datura), wild 

 nightshade (Solanum), turkey mullein (Eremocarpus) , tarweed 

 (Madia), and numerous grasses. ... In southern California the 

 squirrels are fond of the fruit of the prickly pear (Opuntia) ." 



Ground squirrels are provided with more or less extensive, membrane- 

 lined cheek pouches opening inside the mouth, which are used in gather- 

 ing and transporting food (see fig. 13). Often when the animals are 

 scared out of weed patches or bushes, or away from some supply of roots 



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