Table 9. A. Seasonal percentage use of vegetation type by mule deer, 

 compared for three methods of observation and analysis. 



Vegetation Type 



Method 



Sagebrush-Grassland 



Pine-Juniper 



Douglas fir-Juniper 



All Others 



Vehicle Routes 

 Aerial Observations 

 Block Analysis 



Vehicle Routes 

 Aerial Observations 

 Block Analysis 



Vehicle Routes 

 Aerial Observations 

 Block Analysis 



Vehicle Routes 

 Aerial Observations 

 Block Analysis 



snow-free. Overall, the comparison indicated that our use of 

 aerial survey data greatly reduced bias due to differential 

 observability of deer in different vegetation types. It also 

 confirmed Mackie's (1970: p. 33) suggestion that overall use 

 of forested types was much more intensive than observations 

 indicated and that relative use of sagebrush-grassland and 

 other open types was minor, especially during summer and 

 autumn . 



Influence of Vegetational Diversity on Habitat Use 



Both the number of different cover types and the number 

 of cover polygons per block were considered indicative of 

 habitat diversity. /Amount of "edge" within blocks increased 

 with number of cover types, while both edge and interspersion 

 increased with the number of cover polygons; i.e., a block 

 containing 2 polygons of each of 2 vegetation cover types (4 

 cover units) was considered more diverse than a block 

 containing 1 polygon each of 3 different types (3 cover 

 units ) . 



Deer were not distributed randomly in proportion to the 

 number of cover types available per block during any season 

 (summer: X 2 = 582.9, 5 df, P < 0.00001; autumn: X~ 

 df, P < 0.00001; winter: X 2 = 1042.0, 5 df, P 

 spring: X 2 = 621.1, 5 df, P < 0.00001). Fewer deer than 

 expected were observed in blocks containing 1 or 2 cover types 

 (Fig. 9.3), while blocks containing 3 cover types were used as 



! = 642.1, 5 

 < 0.00001; 



251 



