DOG-TOWN DIGGINGS 217 



cally protesting at or about something. Cheer- 

 fulness and vivacity characterized this fat, 

 numerous people, but they were always alert, 

 and commonly maintained sentinels scattered 

 throughout the town. 



While numbers were visiting or playing a few 

 were feeding. They appeared to feed at all 

 times of the day. But I do not believe that they 

 eat half the food of the average woodchuck. 

 The short grass was the principal food. They also 

 ate of the various weeds around. I do not re- 

 call seeing them eat the bark of sagebrush or 

 any part of the prickly pear. 



Prairie dogs must materially assist in soil 

 formation. Their digging and tunnelling lets 

 dissolving water and disintegrating air into the 

 earth and deepens the prairie soil. 



The conge-sting population in time increases 

 the soil supply. In places and for a time this 

 new soil seems to be helpful in increasing the food 

 supply, but after a time in many towns food 

 becomes scarce. Food scarcity causes move- 

 ment. I have heard that the entire population 

 of a dog town, like an entire species of migrating 

 birds, will leave the old town and trek across 

 the plains to a site of their liking. 



A generation ago the prairie dog population 

 must have exceeded two hundred millions. 

 It was scattered over the great plains and 



