ZOOLOGICAL 
654 
THIRTEEN-LINED SPERMOPHILE. 
of the 
phases of balance in animal life that we are en- 
deavoring to illustrate in the exhibition of the 
right here that we evidently note one 
animals under discussion. 
The ground squirrels of the United States, 
together with the members of the Mouse and 
Rat Family, the Murida, stand as a_ positive 
menace to the agriculturists—some of them 
constituting a menace to 
humanity generally. If 
these creatures were not 
kept in vigorous check 
they literally 
overrun vast regions of 
would 
the globe. The march 
of civilization has re - 
sulted in the marked in- 
crease of a number of 
species that thrive upon 
the products of tilled 
soil. The ground squir- 
rels, forming a large 
North American group, are particularly common 
in the western portion of the United States, 
where they are commonly called “gophers.” They 
have also been grouped under the title of sper- 
mophiles,—meaning seed-lovers. This title is 
quite appropriate, as the vast majority of the 
species feeds principally upon grain and seeds. 
They live in burrows in the prairie country, 
some in actual desert regions, and in the great 
wheat belts are altogether at home, in the midst 
of plenty. 
Of the spermophiles north of Mexico, there 
are thirty-one full species and forty-two sub- 
species. In the cultivated areas their most de- 
structive habit is the digging up of seed grain. 
Yet it should be explained that some species eat 
quantities of destructive insects, such as grass- 
hoppers, beetles, cut-worms and crickets, and in 
this way partly compensate the farmer for the 
grain they devour. The ground squirrels or 
spermophiles are prolific, bringing forth seven 
to ten young in a litter. Their enemies are the 
SOCIETY 
BULLETIN. 
rodent-eating snakes, foxes, badgers, skunks, 
Of these little animals exhib- 
ited in our series to demonstrate the destructive 
hawks and owls. 
species and their natural destroyers, the thir- 
teen-lined spermophile, (Citellus tridecemlinea- 
tus), is one of the smallest, though most widely 
distributed The 
and characteristic, consisting of pale yellow 
species. pattern is striking 
bands, separated by rows of yellow spots on a 
dark brown ground-color. 
The Richardson spermophile, (Citellus rich- 
ardsoni), of northern Montana, North Dakota 
and the region immediately northward as far as 
the Saskatchewan, is another of the ground 
squirrels in our special collection. It looks much 
like a miniature prairie “dog,” except for the 
proportionally longer tail. It is notoriously 
destructive to grain. 
Like a number of other 
species among the sper- 
mophiles, it passes the 
winter in a state of hi- 
bernation, during which 
period its blood circula- 
tion is greatly retarded, 
to such an extent, in 
fact, that a hibernating 
squirrel might be mis- 
taken for a dead crea- 
ture. 
JERBOA. 
As examples of mam- 
mals that constantly menace the welfare of man- 
kind, owing to their persistent multiplication, 
our series of the destructive rodents necessarily 
embraces a number of species of the rats and 
mice, these representing the largest of the fami- 
lies among the rodents, or gnawing animals, the 
Muride. The common rat, (Mus decumanus), 
despite its insignificant size, must be rated as a 
distinctly destructive species, and one actually 
dangerous to man. With the gradual solving of 
KANGAROO RAT. 
