AMERICAN FOKESTKY 



METHODS OF EXTERMINATION 



Tin- Cnited States Biological Survey has for several years past tried 

 rations meilm-is of exterminating the prairie dog. It has decided that the 

 IIH.M eilertive and economical methods to employ are poisoning with barley 

 mois soaked in strychnine, and suffocating through the introduction of bi- 

 snlphiile of carbon into the burrows. About one-half teaspoonful of the 

 poisone.I l.aii scattered on the hard ground at the mouth of a burrow is 

 snllicient. When the bisulphide of carbon is used it is placed upon some 

 absorptive material and thrust as far into the burrow as possible and then 

 the entrance of the burrow is closed. If the bulk of the animals are de- 

 stroveil l.v poisoning with strychnine in spring or winter when food is scarce, 

 ami the remaining animls subsequently treated with bisulphide of carbon, 

 whole to \vns can be destroped at a cost of not more than 16 or 17 cents per 

 arre, probably less. Other baits that may be used are green alfalfa, green 

 steins of young wheat or barley, and green corn stalks. 



Besides the extensive efforts of the Biological Survey, the praires dogs 

 are fought by the Forest Service. Large areas of natural cattle range are 

 wiihin National Forests, and every effort is being made to put these ranges 

 in perfect condition; hence efforts are made to get rid of both prairie dogs 

 ainl predatory animals. Some persons believe that the decrease in the number 

 of wolves and coyotes has caused an increase in the number of prairie dogs, 

 a nire lialance of nature having been destroyed. It is true that the most 

 inveterate enemies of the prairie dog are the wolf, the coyote, the badger, and 

 the rattlesnake. This list would make one want to take the side of the prairie 

 <\X if one could choose between him and his enemies. But the prairie dog is 

 always the eaten, never the eater. 



Not much has been done as yet; there is not money enough to pay for 

 the material and labor required. However, the work of locating the towns 

 is minplete, and this is one of the most important steps in the work. Such 

 work as the Forest Service has been able to do has been slow but sure. The 

 poisoned .ui-ain method has been used almost invariably. 



Following is the formula perfected and recommended by the Biological 



Survey : 



STARCH-STRYCHNINE FORMULA FOR COATING GRAIN 



Barley, dean grain, free from other seeds ......... 20 quarts 



Jtrychnia sulphate (ground or powdered) ........ 1 ounce 



......................... '.'.'. .'.'.'.'. V.I teaspoonful 



Itarch H.nlmary laundry starch) ...................... i /2 teaspoonful 



I .., -4 -t / * A 



........................................ V/ 2 pints 



tarch in a little cold water and add iy 2 pints of boiling 

 Baking a ,. a , K , r th } solution WMle ^ ^ fav g 



I '' from lumps ; then add the saccharine and beat thoroughly. Now 



' ' ; 11 s ' h veitie bariey and stir ^ tn ^ pLon * 



the gram to dry - men dry * wiu k - indefi - 



''" '"diriary quantities a galvanized-iron washtub is an excellent re- 



