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THE MONTHLY BULLETIN. 



SAN BERNARDINO GOLDEN-MANTLED GROUND SQUIRREL. 

 Callospermophilus chrysodeirus bernardinus (Merriam). 



Other names. — San Bernardino Ground Squirrel; San Bernardino Spermophile ; 

 Yellow-headed Chipmunk, part; Spermophilus bernardinus; Spermophilus chrysodeirus 

 brevicaudus; Citellus chrysodeirus bernardinus; Callospermophilus bernardinus; 

 Tamias chrysodeirus brevicaudus ; Tamias lateralis, part. 



Field characters. — The same as for the Sierra Golden-mantled Ground Squirrel. 

 The slight shortness of tail characterizing this race is certainly not a sufficient differ- 

 ence for notice at any distance. 



Description. — In all pelages : Coloration, as far as we can see after comparing large 

 series of specimens, exactly as in the Sierra Golden-mantled Ground Squirrel. None 

 of the paleness is apparent such as characterizes the Inyo race. 



Variations. — Of the same sort as discussed under the Sierran race. 



Measurements. — Average and extreme measurements, in millimeters, of twenty 

 full-grown specimens from the San Bernardino Mountains are as follows : Ten males : 

 total length, 260 ( 240-278) ; tail vertebra?, 80 (68-90) ; hind foot, 40 (36-43) ; 

 greatest length of skull, 43.5 (42.0-45.6) ; zygomatic breadth, 26.6 (25.5-27.6) ; 

 interorbital width, 10.7 (10.1-11.3). Ten females: total length, 251 (236-271); 

 tail vertebrae, 78 (72-86) ; hind foot, 38,5 (35-42) ; greatest length of skull, 41.8 

 (40.4-43.0) ; zygomatic breadth, 25.5 ( 24.2-26.8) ; interorbital width, 10.2 (9.7-10.8). 



Unfortunately, ear measurements from fresh specimens are not available ; but dried 

 skins look to have decidedly smaller ears than in either the Sierra or Inyo race, this 

 character being especially noticeable in the young. It will be noted from the above 

 measurements in comparison with those given for chrysodeirus and perpallidus, that 

 the body size of bernardinus is just the same as in the others, while the tail length 

 is decidedly less. This, then, is the character of the subspecies bernardinus, short- 

 ness of tail ; and it shows up well in a series of specimens, even very young ones. 

 However, this difference in tail length between adults of bernardinus and of chryso- 

 deirus averages but somewhat less than half an inch, and individual variation brings 

 overlapping in a certain proportion of specimens. In other words, an extra short- 

 tailed chrysodeirus might even have a longer tail than an extra long tailed bernardinus. 

 The race bernardinus is but slightly and incompletely differentiated. 



No weights are available for this subspecies. 



Type locality. — San Bernardino Peak, San Bernardino Mountains, San Bernar- 

 dino County, California (Merriam, 1893, p. 134). 



Distribution. — Restricted to the relatively small area, not more than twenty-five 

 miles in greatest width, comprised in the higher parts of the San Bernardino Moun- 

 tains (see fig. 24). Belongs to the Boreal zone and upper part of the Transition. 

 Extends up to the very summit of San Gorgonio Peak, 11,485 feet altitude, and 

 down locally, as near Bear Lake, to 6,700 feet (Grinnell, 1908, p. 141). 



Specimens examined. — A total of 84, from the following localities, all in San 

 Bernardino County, California : San Gorgonio Peak, 2 ; Dry Lake, 3 ; South Fork of 

 Santa Ana River, 14 ; Sugarloaf Mountain, 2 ; Bluff Lake, 61 ; Bear Valley, 2. 



Far separated by desert and lowland from the habitat of its near 

 relative on the Sierras, the Golden-mantled Ground Squirrel of the San 

 Bernardino Mountains has developed slight peculiarities which make it 

 recognizable as a distinct race. It has the most restricted range, prob- 

 ably, of any species or subspecies of ground squirrel in the state. It 

 seems strange that it should be wholly lacking as an inhabitant of the 

 San Gabriel and San Jacinto mountains, so near by on either 

 hand and seemingly of quite similar environment to the San Ber- 

 nardinos. On the higher parts of the San Bernardino Mountains it 

 is certainly not on the wane, but thrives greatly, perhaps outnumbering 

 all the other members of the squirrel family put together. 



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