25 

 estimate that the breeding population of Ferruginous Hawks 

 in Beaverhead and Madison counties comprise a minimum of 132 

 pairs. This estimate may be conservative for additional 

 segments of public and private land have yet to be surveyed. 

 These areas include the area between Sweetwater Creek and 

 the Blacktail Wildlife Management Area which contains the 

 Robb Ledford Wildlife Management Area where eight nests have 

 been located [at least two active territories (E. C. 

 Atkinson and Dennis Flath, unpub. data)]. 



Throughout the study area, active nests appeared to be 

 clumped in their distribution with areas containing decadent 

 nests situated between these active "complexes". Vegetative 

 cover appeared to be similar between the areas of high 

 activity and the unoccupied areas similar to the situation 

 described by Fitzner et al. (1977) in southeastern 

 Washington and Ann Black (pers. comm.) in Phillips County, 

 Montana. I believe that the variables leading to these 

 observations warrant further study. Ultimately, such 

 factors as high site-fidelity, complexes containing related 

 individuals, differential prey populations, grazing 

 practices and the subsequent changes in vegetation 

 associated with different intensities of grazing, in 

 addition to human disturbance may all play a role in 

 determining what areas in southwestern Montana are occupied 

 by breeding Ferruginous Hawks. 



The population of Ferruginous Hawks in southwest 

 Montana is one of the most productive groups studied to 

 date. Additionally, these breeding pairs show very high 

 nesting density. Both of these factors lend make southwest 



