THE , CALIFORNIA GEOUND SQUIRREL. 
7 
of their enemies. Dikes, levees, roadways, and embankments of all 
kinds attract them and are often seriously undermined by their bur- 
rows. In the irrigated districts their underground tunnels, like those 
of the pocket gophers, frequently cause breaks costing large sums to 
repair. Thus in May, 1910, ground-squirrel burrows caused such a 
serious washout in the Turlock Canal in Stanislaus County that the 
line of the canal had to be changed at a cost of $25,000. The break 
occurred during the latter half of May, and the labor of rebuilding the 
waterway occupied about three months, depriving the ranchmen of 
w^ater at the very time it was most needed for the irrigation of their 
alfalfa and other products and entailing a loss of upward of half a 
million dollars. 
NATURAL ENEMIES. 
The principal natural enemies of the California ground squirrel are 
coyotes, badgers, gray foxes, bobcats, weasels, golden eagles, and 
rattlesnakes. 
THE GROUND SQUIRREL AS AN ARTICLE OF FOOD. 
Ground squirrels are good to eat and a few years ago were regu- 
larly sold in the San Francisco markets. They have always been 
prized by the Indians, who roast them over the coals and devour 
them eagerly. Old animals at times have a rather strong flavor, but 
the young of the year are usually excellent. Recently, however, since 
the squirrels have been found to be carriers of plague, the Public 
Health and Marine-Hospital Service has warned the public of the 
danger of handling the animals. 
PLAGUE-INFECTED GROUND SQUIRRELS. 
The Asiatic or bubonic plague is now endemic among the ground 
squirrels in the region immediately east and south of San Francisco 
Bay. In this area during the past year the Public Health and 
Marine-Hospital Service has found more than 387 squirrels infected 
with plague. The squirrels contracted the disease, without doubt, 
by contact with European rats at the seaport towns about the bay. 
Ten human cases, of which seven or eight were fatal, resulting from 
ground-squirrel infection, have been reported. 
If funds had been available before the infected squirrels had spread 
south of San Fjrancisco Bay and east of the San Joaquin River the 
animals could have been completely exterminated over the infected 
area. This could have been accomplished at a cost of less than 
$100,000 by cutting a broad swath through the ground squirrels' 
habitat from the south end of the bay easterly to the San Joaquin 
River, and then working back until they were exterminated over the 
entire area. But means were not at hand and the disease among the 
