THE PRAIRIE DOG OF THE GREAT PLAINS. 
208 
being entombed by the clog. If the mother of the young do'js, on a return to tin- 
home hole, finds that a snake has intruded, she at once sets up a i)ecuHar cry or hark, 
to which all the citizens of the town at once respond. They gather about the hole, 
and in a moment all are at work filling it up. The (luickness with which they can 
do this is remarkable. When the hole is filled they l)utt and pack the dirt in the 
mouth of the hole till it is almost as hard as the prairie adjacent. There is no chance 
for an escape of the invader. He is sealed up in his toml). The snake nnderstands 
this danger, and is prepared to escape from it on the least warning. A handful of 
dirt thrown in a hole where the snake is will bring him. with all speed out of the 
hol'e, because he is under the impression that the dog.-^ are aljout to seal him up.' 
There are other enemies also, such as cougars or mountain lions, 
bobcats, eagles, hawks, and owls, but most of them are not sufficiently 
abundant on the Great Plains to be regarded as important factors in 
holding the prairie dog in check. Still, in some localities, hawks and 
owls kill large numbers of the young. They should ])e protected and 
encouraged. 
RECENT INCREASE AND SPREAD OF PRAIRIE DOGS. 
Formerl}^ the area of available land in proportion to the population 
was so great that little attention was paid to such pests as prairie dogs 
and gophers. But in recent years the development of improved 
methods of farming, including irrigation and artesian water supply, 
has led ranchmen to push farther and farther westward over the semi- 
arid plains, until agriculture and stock raising have invaded most parts 
of the prairie dog's domain, the land holdings have decreased in size 
and increased in value, and the depredations of pests are more keenlv 
felt. 
On many parts of the plains prairie dogs are now more al)und:int 
than formerly and their colonies have overspread extensive areas pre- 
viousl}^ unoccupied. This is due to the coming of the white man, 
whose presence favors their multiplication in two ways — (1) l)y increas- 
ing the food supply, and (2) by decreasing the animal's natural ene- 
mies. The white man cultivates the soil and thus enables it to support 
a larger number of animals than formerly; at the same tim(> he wages 
warfare against the covotes, badgers, hawks, owls, snakes, and other 
predatory animals which had previously held the prairie dogs in cheek. 
Thus favored, the prairie dogs have multiplied until they have beconu' 
one of the most pernicious enemies to agriculture. The increase of 
late years is well known to ranchmen on the i)lains. ])ut for the infor- 
mation of others a few definite instances recently cidlected by my 
assistants may V)e of interest. 
Richard Harrison, of Blunt, S. Dak., states that ten years ago thiM-e 
were possibl}" 25 occupied burrows on his land: the animals increa>eii 
slowly and six years ago not more than 10 acres were infested. Since 
then the increase has been so rapid that at present the area t\\c\ cH'cupy 
covers about 160 acres. 
1 American Field, p. 194, March 11, 1899. 
