Page:Natural History of the Ground Squirrels of California.djvu/72

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short-cylindrical or elliptical in shape, and measure 6.5 millimeters in diameter by from 15 to 22 in length.

There were two nest cavities in the system unearthed, an old one, and the one in use. The latter contained a dry, hollow mass of frazzled juniper bark and weathered stems and blades of grass. The female parent and six third-grown young were overtaken farther along in the burrow system, near one terminus of it, but that the nest had but recently been vacated was shown by its feeling of warmth to the touch and the presence of numerous lively fleas. The female proved a tartar in defense of herself and young, biting effectively with her sharp incisor teeth and scratching with her strong claws. This was as a final recourse, however, as the first endeavor on the part of all the occupants, when the burrow was opened up, was to escape and run to the nearest shelter, such as offered by some neighboring burrow, or by a flat rock. As far as our observations went, there was no indication that the adult male lives in the same burrow with the female, or has, indeed, anything to do with the rearing of the young.

The burrow system in question was found to be 66 feet long, including the various windings and all of its branches. Its average diameter was about 2½ inches, and the volume, or cubical air content, 3½ cubic