21 

 missed nesting attempts that were aborted early in the 

 season. The densities of active Ferruginous Hawk 

 territories were lower than those determined by Myers 

 (1987) , however, the study-wide value was still greater than 

 the nesting density found in southeastern Montana (Ensign 

 1983, Wittenhagen 1991). Myers (1987) observed that the 

 highest nesting density was in the Mountain Mahogany 

 ( Cercocarpus ledifolius ) Association, whereas the lowest 

 density occurred in the Sagebrush Steppe Association 

 (Kuchler 1964) . I surveyed very little of the Mountain 

 Mahogany Association, finding one occupied nest, and the 

 highest densities that I recorded were in the Sagebrush 

 Steppe Association (Diamond Butte Area) and the Foothill 

 Prairie Association (Frying Pan Basin Area) . The nesting 

 densities in these latter two areas were comparable to, yet 

 still lower than, the densities reported by Myers (1987) for 

 those two associations. Interestingly, both of the above 

 survey areas contained a considerable portion of private 

 lands; more so than any of the other six areas inventoried. 



The number of alternate nests contained within each of 

 the sixteen active territories was very similar to the 

 number/territory described by Myers (1987) , with the 

 majority of territories in each study containing no 

 alternate nests. 



Productivity per occupied territory was high and 

 similar to the values reported for 1985 and 1986 by Myers 

 (1987). The value of 1.97 fledglings per nest is adequate 

 to maintain a stable population of Ferruginous Hawks based 

 upon minimum requirement of 1.5 fledglings per nest assuming 



