4 

 Lewis Myers [Bureau of Land Management (BLM) , Dillon 

 Resource Area] . The surveys that I performed in 199 2 led to 

 the completion of an inventory program for the majority of 

 BLM holdings in Beaverhead and Madison counties, Montana 

 (Figure 2) . 



METHODS 



I initiated field surveys for nesting Ferruginous Hawks 

 on 24 June 1992 and continued until 1 August 1992. Six 

 major areas totalling 42,890 ha (105,900 acres) to be 

 surveyed were delineated by Dillon Resource Area (BLM) 

 biologist Jim Roscoe (Appendix A) . Area boundaries were 

 transferred to 7 . 5 minute U.S. Geological Survey (USGS) 

 topographic maps for use in the field. 



Surveys were conducted on foot by walking ridges while 

 intermittently stopping to survey the surrounding areas for 

 stick nests and hawks with 9X binoculars and/or 20X spotting 

 scope. Additionally, some areas were surveyed via 4x4 

 truck, again, coupled with scanning through binoculars, 

 often from exposed promontories. One aerial survey from a 

 fixed-wing aircraft was performed on 16 July. 



Locations of Ferruginous Hawk and other raptor nests 

 were plotted on 7 . 5 minute guads and a "Raptor Nest 

 Inventory" form (BLM) (Appendix B) was filled out for each 

 Ferruginous Hawk nest observed. I categorized the substrate 

 supporting the nest into the following: ground = nest 



