The range use and food habits data obtained during 

 1960-1964 indicated that opportunities existed for competition 

 between mule deer and elk and between mule deer and cattle on 

 the study area. The probable degree of competition was light, 

 except for some seasons. The greatest overlap in range use 

 and food habits of deer and elk occurred during the period 

 from April to September, while that between mule deer and 

 cattle occurred in April and May. Opportunities for 

 competition in spring centered around intensive use of the 

 sagebrush-grassland type by all 3 species. The potential for 

 competition between mule deer and elk during summer was 

 related to significant use of timbered vegetation types and 

 similar forage plants by both species. In addition, 

 competition could become more severe; 1) during periods of 

 drought, 2) if stock water sources were constructed on 

 terminal portions of large ridges or on smaller ridges within 

 timbered breaks and extended intensive grazing to those areas, 

 or 3) if numbers of elk using the area increased greatly. 



Considering relative distribution and varying intensity 

 of use of the area by mule deer, elk, and cattle on a yearlong 

 basis, there was little overlap between primary cattle range 

 areas and primary mule deer habitats (Fig. 9.7). Primary 

 areas for use by cattle were the broad open plains, major open 

 ridgetops, and larger coulee bottoms. Mule deer primarily 

 used steeper, diverse or timbered terrain between major 

 ridgetops and major coulee bottoms. Comparison of overall 

 spatial distribution of mule deer and elk also indicated 

 relatively little overlap, especially when seasonal patterns 

 were considered. 



Mule Deer and Elk 



A comparison of the yearlong density distribution 

 (intensity of use) pattern for elk during 1976-1984 (Fig. 9.8) 

 with that for mule deer (Fig. 7.1) indicated little overlap in 

 areas of greatest intensity of use for both species. A 

 simultaneous plot of the 2 highest categories of intensity of 

 use for both species (Fig. 9.9) indicated only 11.2% of the 

 high density blocks for both species were the same. Of high 

 density elk blocks, 26.9% were also high density mule deer 

 blocks and 19.1% of high density mule deer blocks were also 

 high density elk blocks. 



The general pattern of dispersion of elk on the study 

 area, however, was similar to that for mule deer. That is, 

 moderate to dense concentrations generally extended across 

 broken terrain along slopes and coulees between major 

 ridgetops and major coulee or river bottoms. Thus, the 

 primary habitat for elk and mule deer centered in and around 

 essentially the same land areas, although areas used 

 intensively by elk extended on to primary cattle range more so 



264 



