-12- 



Additlonal time was spent searching reservoirs, prairie dog towns, etc. for 

 unusual species. Ten of the largest prairie dog towns were completely searched 

 on foot in an effort to locate possible evidence of black-footed ferret {Mustela 

 nigripes) and burrowing owl (Athene ounicutaria) activity. 



All species listed as being of special interest or concern for Montana are 

 from a list compiled by Flath (1979a). 



Scientific names in this report are from the following sources (with a few 

 minor exceptions): vegetation, Hitchcock and Cronquist (1976); birds, Skaar 

 (1980); mammals, Hoffmann and Pattie (1968); reptiles and amphibians, Stebbins 

 (1966). 



Vegetation Descriptions 



The vegetation map of the study area was developed through modifications of 

 the infrared aerial photography vegetation interpretations (Ecological Consulting 

 Services Division, Helena, Montana) provided for the Prairie and Kinsey planning 

 units (the study area occupies portions of these units) . Modifications included 

 separating the upland-grassland type into the sage-grassland and grassland 

 types, and delineating a major creek type. These modifications resulted after 

 aerial and ground reconnaissance of the study area revealed that separation of 

 these types was justified. 



Vegetation frequency (% occurrence in 100 2 x 5 dm frames) measurements were 

 made by placing a 2 x 5 dm frame at 20 m intervals along the 2000 m bird tran- 

 sect lines in each major vegetation type. Only living plants which were rooted 

 within the frame were counted. Extreme drought conditions resulted in the 

 undersampling or non-sampling of many normally occurring species. 



Relative Abundance 



The relative abundance of nongame species on the area was determined by the 

 number of observations, variety of vegetation types utilized, season of obser- 

 vation, and breeding status. This information was compiled and the following 

 method of delineating relative abundance developed: 



Abundant: >75 observations on the area and occurring in most 

 vegetation types. 



Common: Observed 10-75 times and occurring in at least two of the 

 vegetation types. 



Uncommon: Observed 3-10 times and usually restricted to one 

 vetetation type. 



Rare: Observed 1-3 times on the area and limited to one vegetation 



type. 



Exceptions to the above are explained in the text of the report (e.g. species 

 that undoubtedly occur on the area but were not seen during the course of the 

 study due to low observability and other variables, etc.). 



