BUREAU OF BIOLOGICAL SURVEY. 259 



about one-sixth of the State. Another large area in southern Col- 

 orado was systematically poisoned with excellent eifect. The experi- 

 ence gained in these operations indicates that with the full coopera- 

 tion of local stockmen poisoning will prove a very important factor 

 in disposing of the predatory-animal pest. 



The following predatory animals were taken by hunters under the 

 direction of this bureau, during the present year: 849 wolves, 26,241 

 coyotes, 85 mountain lions, 3,432 bobcats, 30 lynxes, and 41 bears. 

 Every effort is being made to have the predatory-animal hunters kill 

 only such bears as are known to be destructive to live stock. A small 

 number of bears, however, unavoidably fall victim to traps set for 

 other animals. 



Since the bureau began its operations against predatory animals 

 the skins of 70,732 have been taken and a vast number in addition 

 have been killed by poison. Reports from various sections of the 

 country where poisoning operations have been conducted show the 

 finding of thousands of dead coyotes. The well-known fact that the 

 great majority of poisoned animals are never found, coupled with 

 the scarcity of coyotes in the poisoned areas, indicates the effective- 

 ness of the work. 



The control of rabies in the regions affected is under the super- 

 vision of the inspectors in charge of the regular predatory-animal 

 work. Field reports indicate a continuance of this disease among 

 wild animals, but show that the work of the bureau has been effective 

 in limiting its spread and in suppressing it in many places. Al- 

 though the disease occurs over a vast territory, the results of the 

 work give promise of its eventual suppression without, as was at one 

 time feared, its spreading over the entire Rocky Mountain region. 



As an indication of the losses due to predatory animals it may be 

 stated that the chairman of the State Live Stock Board of Utah 

 estimates an annual loss in that region amounting to 500,000 sheep 

 and 4,000,000 pounds of wool. The president of the Xew Mexico 

 College of Agriculture, as a result of a survey of conditions in that 

 State, estimates an annual loss there of 3 per cent of the cattle, or 

 34,000 head, and 165,000 sheep. A single wolf killed by one of the 

 bureau hunters in southern New Mexico was reported by stock 

 owners of that vicinity to have killed during the preceding six 

 months 150 head of cattle valued at not less than $5,000. In July, 

 1917, two male wolves were killed in Wyoming which in May had 

 destroyed 150 sheep and 7 colts. Another pair of wolves killed near 

 Opal, Wyo., were reported to have killed about $4,000 worth of stock 

 a year. Another Wyoming wolf, trapped in June, 1918. had killed 

 30 cattle during the spring. Exceptionally skillful hunters and 

 trappers are detailed to capture these especially destructive animals 

 as rapidly as they are reported, and the success in capturing them 

 has resulted in a great addition to the meat output of the ranges. 



RODENT CONTROL. 



Injurious rodents, as prairie-dogs, ground squirrels, jack rabbits, 

 and pocket gophers, mainly west of the Mississippi River, are in the 

 aggregate enormously destructive to cultivated crops and native 

 forage, thus directly reducing the food output from farms and lessen- 

 ing the carrying capacity of the range for live stock. The control 



