Natural History of the Ground Squirrels of California/Illustrations

by Joseph Grinnell and Joseph Dixon

 

ILLUSTRATIONS.

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Plates.

Page

Plate 1.

California Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5

Plate 2.

Douglas Ground Squirrel and Oregon Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

52

Plate 3.

Belding Ground Squirrel and Sierra Golden-mantled Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

70

Plate 4.

Yuma Round-tailed Ground Squirrel and Mohave Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

76

Plate 5.

Desert Antelope Ground Squirrel and Fisher Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

98

Figures in text.

Page

Fig. 01.

Ears of several species of ground squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

9

Fig. 02.

A typical example of the California Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

13

Fig. 03.

Four characteristic poses of a California Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

15

Fig. 04.

Mound and burrow entrance of a California Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

16

Fig. 05.

"Hog-wallow" land, showing burrow of the California Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

18

Fig. 06.

Plot of excavated burrow of a male "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

19

Fig. 07.

Plot of excavated nesting burrow of a female "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

20

Fig. 08.

Plot of excavated coloniel burrow-system of "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

21

Fig. 09.

Nest of male "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

23

Fig. 10.

Nest of female "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

24

Fig. 11.

Nest and small young of "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

25

Fig. 12.

Diagram showing extent and height of breeding season in California Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

26

Fig. 13.

Drawings to show relative extent of cheek-pouches in California and Belding Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

33

Fig. 14.

Heads of wheat gathered by one "digger" squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

35

Fig. 15.

Metropolis of "digger" squirrels in a grain field ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

36

Fig. 16.

Badly infested hillside ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

41

Fig. 17.

Map showing distribution of the "digger" squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

46

Fig. 18.

Map showing distribution of the Oregon, Belding, Stephens Soft-haired and the Round-tailed Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

61

Fig. 19.

Plot of excavated nesting burrow of Oregon Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

64

Fig. 20.

Life photographs of Oregon, Belding and Sierra Golden-mantled Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

69

Fig. 21.

Plot of excavated burrow of female Belding Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

71

Fig. 22.

Third-grown young Belding Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

72

Fig. 23.

Diagram showing the ranges of California Ground Squirrels according to life-zones ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

78

Fig. 24.

Map showing distribution of the Golden-mantled and Antelope Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

86

Fig. 25.

Hibernating San Bernardino Golden-mantled Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

93

Fig. 26.

Feet of Desert Antelope, Stephens Soft-haired and California Ground Squirrels, to show tubercles and extent of hairing ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

95

Fig. 27.

Young Desert Antelope Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

101

Fig. 28.

Young Nelson Antelope Ground Squirrel ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

106

Fig. 29.

Adult pair of Nelson Antelope Ground Squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

107

Fig. 30.

Diagram showing relative economic importance of different ground squirrels ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

114

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Note.—Figures indicating page numbers refer to folios at foot of pages