nient — is likely to be the one used. 

 Consequently, methods vary con- 

 siderably from one section of the 

 country to another. When factors 

 such as range utilization, relative 

 abundance of ground predators, 

 time of lambing, presence and ab- 

 sence of buffer species, availability 

 of carrion, unseasonal freezes or ex- 

 tremely hot weather, screw worms, 

 disease, and poisonous plants are 

 taken into account, any attempt to 

 fit the golden eagle into the picture 

 becomes a complicated problem. 



During this study, two areas in 

 Avhich combined cattle and sheep 

 raising was the principal land use 

 were compared. One of these was 

 country north of Fort Collins, Colo., 

 on the eastern piedmont plain of 

 the Rocky Mountains in northern 

 Colorado and southern Wyoming; 

 the other the sheep-raising country 

 of west Texas. 



The Colorado-Wyoming area in- 

 cludes rolling foothills, scattered 

 blutl's and buttes, and open prairie. 

 In general, it is Upper Sonoran 

 })i'airie grassland with brushy cover 

 on the slopes. The resident eagle 

 population varies from place to 

 place depending on the availability 

 of suitable nesting territories, but 

 it approximates one pair to a town- 

 ship. Sheep usually are herded in 

 flocks of about GOO to the herder 

 (hiring the late-winter and prelamb- 

 ing season. Lambing is from 

 March 25 to mid-May, and usually 

 occurs in sheds with the ewes and 

 lambs being confined for 10 days. 

 The flocks are kept under close su- 

 pei'visioii until summer herds of ap- 

 proximately IjoOO lambs and ewes 



are formed. Grazing pressure va- 

 ries from moderate to heavy. 



In this region, sheepmen feel that 

 the golden eagle is no particular 

 problem. W. H. Delvin, foreman 

 for one outfit in the Colorado area, 

 stated that he has neither seen nor 

 lieard of an eagle's killing a lamb 

 or a sheep in this area during his 

 20 years of experience. On the 

 other hand, his observations lead 

 him to believe that they are quick 

 to find and devour any sheep dying 

 from other causes. 



The Texas area west of the Pecos 

 is devoted to cattle (GO percent) and 

 to sheep and goats (40 percent). 

 Topographically, this region is 

 characterized by scattered moun- 

 tain ranges sejDarated by rolling- 

 hills and flat valleys. The flora is 

 semiarid grassland or scrub in the 

 lowlands, diffusing into scattered 

 brushy cover on the steeper slopes. 

 Although the eagle j)<)pulation has 

 been disrupted in recent years, early 

 observations indicate that before 

 control operations were initiated the 

 golden eagle population compared 

 favorably in numbers with that in 

 the Colorado- Wyoming area. Sheep 

 are restricted to fenced areas. The 

 peak of the lambing season is about 

 March 15, although some young are 

 born as early as December. For the 

 most i^art, lambing is in pastures 

 rather than in sheds. ( Irazing pres- 

 sure varies from heavy to extremely 

 heavy, and land use may be abusive. 



In the Texas area, many ranchers 

 consider the golden eagle one of the 

 most detrimental factors with which 

 they have to contend in raising 

 sheep. Even though observations of 



27 



