2 THE C Al.l I'OKN lA (iUOrXl) SQl' 1 HllKL. 
It has two near relatives — the Doiighis ground squirrel (Citellus 
douglasi), which ranges from the nortli side of San Francisco Bay 
northward to the Cohimbia River; and the Rocky Mountain or 
Phitcau ground squirrel {Citellus granimurus) , which in California 
is known only from the canyons of the Colorado River and the Provi- 
dence Mountains on the east side of the Mohave Desert. 
The California ground squirrel, because of the extent of its range, 
which covers the greater ])art of the agricultural lands of the State; 
because of the magnitude of the losses it causes by eating grain, nuts, 
fruit, and other crops; and because of its dangerous character as a 
carrier and disseminator of bubonic plague, is, of all our s})ecies, the 
one of greatest consequence to man. The danger to human life by 
the spread of plague so far exceeds in importance the harm done by the 
destruction of crops that the duty of checking its increase is no longer 
merely of local interest but has become a matter of national concern. 
RANGE. 
The California ground squirrel, as shown on the accompanying 
map (fig. 2) , ranges from Lassen Butte and Susanville in northeastern 
California southward, east of the Sacramento Valley to San Francisco 
Bay, and south of the bay overspreads practically the entire State 
and pushes southward into the peninsula of Lower California, avoid- 
ing only the higher mountains and the more arid deserts. Its hand- 
some subspecies ^s/teri inhabits Kern and Owens valleys, the borders 
of the Mohave Desert, the upper parts of San Gorgonio Pass, and 
other localities in southern California, and occurs as far east as the 
Coso, Argus, and Panamint mountains. 
HABITAT AND HOME. 
The Beechey ground squirrel abounds along the ocean shore from 
San Francisco southward; it inhabits the open plains of the great 
interior valley of California, the grassy chaparral slopes of the foot- 
hills, the rocky walls of canyons, and in places the more open parts 
of the yellow pine forest of the mountains. It lives in underground 
burrows which usually are grouped in colonies. The colonies may 
be located on bare open plains, on the grassy slopes of foothills, or 
about the roots of trees — particularly the great valley oaks with hol- 
lows in their trunks and limbs. The burrows var}' in number from a 
few to hundreds, and by the union of contiguous colonies sometimes 
reach a total of thousands and cover almost continuously many hun- 
dreds of acres.' In places they are so near together as to fairly honey- 
comb the ground. Well-beaten paths, 2^ to 3 inches broad, lead 
from burrow to burrow and radiate to the adjacent feeding grounds. 
Many of them extend for considerable distances and by intersecting 
