BUREAU or BIOLOGICAL SURVEY. 349 



<ranized campaif^ns against these pests. In Kansas, after years of 

 effort, extermination of prairie dogs was accomplished except for a 

 few scattering small towns; through neglect of landowners to com- 

 plete the work, reinyasion of adjoining cleared areas is beginning to 

 occur. Effort is now being concentrated upon these small areas of 

 infestation, involving 2~> to 40 acre tracts, which are widely scattered 

 throughout the middle and western counties. 



Similar illustrations may be cited of effective work in the enor- 

 mous cami)aigns now being waged against ground squirrels. In 

 Camas Prairie, a fertile valley inclosed by mountains in Camas 

 County, Idaho, where a heavy infestation of Columbia ground 

 sfpiirrels was on the point of driving out the settlers, relief was 

 afforded through the organization of a campaign against the pests, 

 with the result that at present scarcely a ground squirrel can be 

 found in this area, involving 59,000 acres. In North Dakota the Rich- 

 ardson ground squii-rel, commonl}' known as "gopher," formerly 

 caused an annual crop loss estimated by State officials at $6,000,000 

 to $0,000,000, tlepending upon seasonal conditions. The eradication 

 compaigns have now progressed to a point where in many counties 

 these ground squirrels are no longer looked upon as a menace by 

 the landowners, but merely as occasional objects of interest and 

 curiosity. There is a strong tendency under these circumstances 

 for landowners to discontinue the concerted campaign to complete 

 their eradication. Every effort, however, is being made to have this 

 work continued in such counties in order to prevent any possibility 

 of the animals increasing to a point where they may again become 

 destructive of crops. Indolence and neglect can be the onl}' possil:)le 

 reason for such a condition arising, as under the leadershi]) of the 

 bureau and county agents the farmers have become thoroughly fa- 

 miliiir with and experienced in effective measures for destroying 

 these animals. 



In the campaigns against prairie dogs and ground scjuirrels dur- 

 ing the year, 10.117.737 acres of Federal, State, and private lands 

 were given a first poison treatment, and follow-up work was done 

 on 15.172,709 acres. Through State and county appropriations and 

 funds expended by individual landowners, cooperative funds were 

 conti-ibuteil amounting to $841,000. The (juantity of poisoned grain 

 di-tiMl)Uted amounted to 1,010 tons, while tlie numl)er of farmers 

 and stf)ckmen acti\ely cooperating numbered l'il,435. The work 

 resulted in a sa\ ing of crops for the year estimated at $10,000,000. 



POCKET GOPHERS. 



Extensive work has been done during the year in demonstrating 

 methods of destroying jiocket gophers and organizing comnuniity 

 campaigns agsiinst them in Kansas, Nebraska, Idaho, Oregon. New 

 Mexico, and Arizona. Many farmers report killing as high as 95 

 per cent of the j^ests with oue a|:)i)lication of poison. The animals 

 rx-cur in every State west of the Mississijipi Kiver, and are especially 

 injuiious to alfalfa and grazing lands, hay meadows, orchards, and 

 root crops. They often luin the stand of alfalfa by cutting off the 

 tap i-oots. and in Kansas. State officials estimate the annual loss to 

 the alfalfa growers alone from this source at $5,000,000. Pocket 

 gophers greatly reduce the (juantity of hay that can be harvested, 



