PRAIRIE-DOGS 155 



"prairie-dogs" on the Canadian plains; it is to 

 be distinguished by its slightly larger size, dis- 

 tinctly brownish color, and very short tail 

 (two inches), which is flat and black toward the 

 end. 



The prairie-dog is about a foot long, and 

 robust, with strong limbs and claws. It dwells 

 in colonies, whose permanent ''towns" of bur- 

 rows, each marked by a hillock of earth about 

 the entrance, spread densely over many acres 

 under the natural prehistoric conditions, but 

 now sometimes cover hundreds of square miles. 

 The burrows are deep and extensive, and at 

 first go down at a very steep slope to a depth 

 of twelve to fifteen feet, when they turn hori- 

 zontally, and here and there branch into cham- 

 bers, some of which are family rooms, while in 

 others fodder is stored, or refuse and dung are 

 deposited. The mound about the hole is 

 packed hard, not only by the tramping of the 

 animals, but by crowding it down with their 

 noses ; this hillock prevents water from running 

 into the burrows when the plain is flooded by 

 heavy rains, and also serves as a tower of ob- 

 servation. 



