118 ANNUAL HKPORTS OF DEPARTMENT OF AOKICULTURE, 



>'alley should be made. Such a campaign may be urged on the double 

 ground of the public health and the advantage of the farmer, since 

 this mammal is a very serious pest, not only in this particular valley, 

 but wherever grain is sown in Washington, Oregon, Idaho, and Mon- 

 tana. In connection with a study of the local wild mammals, an 

 assistant of the Biological Survey during the coming season will 

 demonstrate to the people within the infested district the best method 

 of exterminating this ground squirrel and other wild mammals that 

 carry ticks. By means of State or county cooperation the small tick- 

 carrying mammals of the western side of Bitterroot Valley, the area 

 chiefly affected, could be exterminated at a comparatively small out- 

 lay of time and money. 



PRAIRIE DOGS. 



Prairie dogs continue to be a scourge to larmers in many sections 

 of the Middle AVest, and they exact heavy toll also from the stockmen 

 by eating nutritious wild grasses which form the main reliance of 

 range cattle. Their colonies sometimes number thousands of indi- 

 viduals, and as it requires only about 200 to consume the forage of a 

 steer their colonies collectively are a heavy drain on both pasturage 

 and crops. During the year many experiments have been made 

 with a view to finding better methods of poisoning or otherwise 

 destroying these animals without at the same time endangering the 

 lives of valuable birds. 



SILVER FOX INDUSTRY. 



During the past year many inquiries have been received from 

 various parts of the United States regarding the practicability of 

 rearing the silver or black foxes for profit, and there is a steady 

 demand for the Farmers' Bulletin on this subject. Interest in the 

 business has no doubt been stimulated by the enormous prices ob- 

 tained for skins, and even larger sums paid for first-class breeding 

 animals. Efforts are being made to obtain all possible information 

 as to the success of breeders who have engaged in the business with 

 a view to issuing a supplemental report on the industry. 



WOODPECKERS. 



As a class, woodpeckers are among our most useful birds. They 

 destroy numbers of noxious insects and lend effective aid to the 

 preservation of forests, city shade trees, and fruit orchards. A 

 bulletin on these birds was issued during the year, analyzing the food 

 they eat., explaining the ways in which they are of value to the 

 farmer, and indicating methods by which their number may be in- 

 creased by the use of artificial nesting sites. 



