R-USN 



- 3 - 



7-17-31 



And they arc not satisfied norcly to crop tho grass close, they 

 dig out the roots. Thousands of acres of valuable v/cstom range land 

 liavo "boon "bared in tliat v;ay, and r.^y cases of erosion liave "been traced 

 to that danago ty prairie dogs. 



Bat Mr. Day socns to thiiik: the pocket gopher is a nuch v/orsc 

 offender in tliat respect than is the prairie dog. Pocket gophers burrow 

 away rdth apparently untiring efforts. In surrier they throw the dirt 

 frora their burrows up to the surface, piling it up in rounds. TOaen tho 

 snow cones in tho fall, and before it has nclted in spring, the pocket 

 gophers pusli the dirt out of their burrows in the fom of long cliainlike 

 ridges. Tlioso ridges fron ninaturc dikes or earthworks, channels for 

 water fron the nelting snow. That helps the water begin cutting away the 

 soil. 



Later, cone the sliecp and cattle into the ranges. The tranping 

 stoclc break through into the sliallov/ passageways of the pocket gophers. 

 More and deeper channels are nado to carry off the nelting snov/ and rains. 



llr. Day tells ne tliat in nany areas after the forage h-as been 

 destroyed and nach of the surface soil taken off in this trariping of live- 

 stock and washing by rains, weeds and often poisonous plants gain a foot- 

 hold. Of course, th^,t creates a serious range condition. 



The rancher who sits as coroner in the death of liis own cattle 

 fron eating poison plants nay never even suspect the little pocket gopher 

 had nuch to do with starting the conditions which made tilings favorable 

 for those poison plants. 



Those are just a few of the reasons the United States Biological 

 Survey is organizing rodent control units to help keep the nunbers of 

 these injurious rodents witliin bounds. By killing off rodents these u:iits 

 help prevent f-urthcr loss of soil through the erosion started by rodents. 



MIIOUITCELQUIT ; TIae bulletins nentionsd ca:: be had free of charge as 



long as the supply lasts, ^rite for then to this Station 



or to the United States Deprrtuent of Agriculture, a.t T^asliington, D, C, 

 The bulletin on "Canaries, Tl-.eir Care and Llanageraent" is Famcrs* Bulletin 

 No. 1327 and the one on "CottontrJ-l Rabbits in Relation to Trees and 

 Fam Crops" is Famcrs Bulletin No, 702, 



