The California Ground Squirrel is probably known by sight to more people than any other one of our four hundred kinds of native mammals. It inhabits open ground in well-settled territory and it forages abroad during the daylight hours when its movements are most likely to attract attention. Numbers are to be seen from the windows of passing trains, and the traveller by automobile is often thrilled by the narrow escapes of those heedless individuals which dash across the road immediately in advance of him, not infrequently to their own undoing. Then, too, this squirrel has, perhaps, been more widely advertised than any of our other mammals. A few years ago it came into prominence as a proven disseminator of the dreaded bubonic plague, and it has become notorious for its exceeding destructiveness to cultivated crops.
The term "Digger Squirrel" is often applied to this species, more especially in the foothill and mountain regions, in recognition of its burrowing habits, to distinguish it from the tree-inhabiting gray and red squirrels. The book name, Beechey Ground Squirrel, much used in the literature relating to it, is derived from the accepted scientific name Citellus beecheyi. This name, beecheyi, was bestowed upon the animal by its original describer (Richardson, 1829, p. 170) "in honour of the able and scientific Commander of the Blossom," Captain F. W. Beechey. The British ship "Blossom" cruised the Pacific Ocean northward even to Bering Strait during the years 1825 to 1828. Collections of specimens were brought back from many localities visited, including San Francisco and Monterey; among these specimens was one or more of the squirrels in question. These were evidently preserved for the most part by Mr. Collie, surgeon of the ship, who is quoted by Richardson as stating that "this kind of Spermophile 'burrows in great numbers in the sandy declivities and dry plains in the neighbourhood of San Francisco and Monterey, in California, close to the houses. They frequently stand up on their hind legs when looking round about them. In running, they carry the tail generally straight out, but when passing over any little inequality, it is raised, as if to prevent it being soiled. In rainy weather, and when the fields are wet and dirty, they come out but little above ground.'" And further information is given, according, for the most part, with what anyone can see for himself today in the same general region. This attests to the acuteness of observation of Mr. Collie, and also shows how the squirrels had already, some ninety years ago, begun to impress people with their numbers and boldness.
The California Ground Squirrel may be distinguished from other members of the squirrel family by the combination in it of the fallowing characters: essentially ground-dwelling habits, relatively large size, long bushy tail, tall pointed ears, and generally grayish coloration with a three-cornered silvery white patch on each shoulder. Close inspection discloses a finely dappled pattern of coloration (see Fig. 2) such as is not shown in any tree squirrel or in any of our other ground squirrels except its near relatives, the Douglas, Fisher, Rock and Catalina Island squirrels. The detailed descriptions, measurements, etc., as given in the accompanying small-type paragraphs, should be studied for further particulars in this connection.
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