68 ANIMAL LIFE OF CARLSBAD CAVERN 



BLACK-TAILED PRAIRIE-DOG 



Cynomys ludovicianus (Figs. 20 and 21) 



Colonies of these plump little yellowish burrowing 

 squirrels are scattered over the Pecos Valley and on 

 many of the more fertile mesas and mountain slopes. 

 They are generally located on the richest and mellowest 

 soil, where digging is easy, and where the short grass 

 and low vegetation furnish abundant food. Sometimes 

 a colony will cover hundreds of acres, comprising 

 thousands of burrows and great numbers of prairie- 

 dogs; again there will be only a dozen burrows and 

 about as many occupants, and on rare occasions one or 

 two are found alone. Naturally they are not on the 

 limestone ridges about the cave, but they are common 

 along the Black River Valley only two miles to the 

 south, where they lay a heavy tax upon some of the 

 best forage. In places they have dug up and entirely 

 destroyed the vegetation on considerable areas and 

 have been forced to move on to find a better food 

 supply. They prove a serious handicap to stock rais- 

 ing as well as to any form of agriculture, and are gener- 

 ally destroyed in every way possible, mainly by means 

 of poisoned grain scattered about their burrows. 



These prairie-dogs are really large plump squirrels 

 with little, short, flipping, black-tipped tails, short ears, 

 short yellowish fur, and voices somewhat like the yip, 

 yip, yip, of a small dog. 



