234 ANNUAL EEPOKTS OF DEPARTMENT OF AGEICULTXJEE. 



of young animals and growth of fur, effects of light on the color and 

 durability of fur, molting, inbreeding, hybridizing between sub- 

 species, importance of taming the animals, and the practical bearing 

 of individual temperamental differences. The results of these ex- 

 periments are already sufficiently encouraging to warrant an exten- 

 sion to other fur bearers, native and foreign, and the establishment 

 in the near future of a well-equipped breeding station at some suit- 

 able point in eastern United States having a climate requisite for 

 producing high-grade fur. 



Experiments in handling and dressing pelts of the different kinds 

 of fur bearers have been undertaken and are still in progress with a 

 view to recommending, for those wishing to tan or dress furs, the 

 method most satisfactory and involving the least labor and expense. 



A number of moleskins from the northwest coast have been secured 

 and dressed. In size, beauty, and durability they easily surpass skins 

 of eastern and European moles and undoubtedly are destined to 

 become popular. Although moles are small and have such habits 

 that it is not feasible to breed them in captivity, where they are 

 numerous they are worthy of the attention of trappers. 



Investigation into the subject of silver fox farming has continued 

 and a bulletin on the subject will soon be ready for distribution. 



PRAIRIE DOG REPRESSION. 



Increased work was carried on in national forests and on the pub- 

 lic domain in the extermination of prairie dogs. This work has now 

 been practically completed in the Pike, Leadville, and Cochetopa 

 National Forests in Colorado, the Alamo National Forest in New 

 Mexico, the Sevier National Forest in Utah, and the Wichita Na- 

 tional Forest in Oklahoma, where more than 95 per cent of the prai- 

 rie dogs have been destroyed and wide stretches of valuable grazing 

 lands entirely cleared of them. While invasion from adjacent areas 

 is likely to occur, very little effort will be needed to keep the cleared 

 areas free of the pest. 



Active campaigns against prairie dogs are being conducted on the 

 Eio Grande Forest in Colorado, the Coconino and Sitgreaves Forests 

 in Arizona, the Custer Forest in Montana, and the Sioux Forest in 

 South Dakota. Important field operations and demonstrations have 

 also been conducted in Texas, South Dakota, Oklahoma, Wyoming, 

 Colorado, and Arizona. 



Oats poisoned by a process whereby the bitter taste of strychnine 

 is largely eliminated have consistentl;^ given the best results. Usu- 

 ally more than 85 per cent of the prairie dogs on infested areas are 

 Idlled by the first application of the poisoned grain, and on the Pike, 

 Sevier, and Wichita Forests over 95 per cent of the animals were 

 destroyed. The only exception to this highly successful work is the 

 Coconino Forest, where the abundance of a species of blue-stem 

 grass, of which the animals are very fond, causes the prairie dogs to 

 care little for grain of any kind. Poisoning operations of last sum- 

 mer in this forest were made less effective by an unusual amount of 

 rain, and not over 70 per cent of the prairie dogs were destroyed in 

 the poisoning and repoisoning of the areas covered. During the year 

 the work in the field has been so systematized that for the first time 



