CHAPTER 1 



INTRODUCTION AND PERSPECTIVE 



Mule deer (Odocoileus hemionus) are the most widely 

 distributed and abundant of all species of large mammals 

 native to western North America. Important populations occur 

 throughout a broad spectrum of habitats or environments— from 

 relatively moist and dense coniferous forests to dry, open 

 plains and deserts. The quality of these habitats for deer 

 varies greatly as a result of broad differences in physical 

 and biotic characteristics. Many are highly variable 

 environments in which habitat quality also fluctuates 

 seasonally and annually due to variation in weather 

 conditions. Mule deer habitat relationships and population 

 characteristics and dynamics, as well as management 

 opportunities and constraints vary accordingly. However, 

 long-term studies addressing spatial and temporal differences 

 in population ecology and their significance in management 

 are lacking. 



Our studies of mule deer in the Missouri River Breaks of 

 northcentral Montana have provided a 28-year data set on 

 ecology and behavior of the species in a representative, 

 historically important and environmentally variable habitat. 

 The studies began with investigation of range ecology and 

 relationships of mule deer, elk, and cattle on the area during 

 1960-1964 (Mackie 1965, 1970). This provided basis and 

 methodology for continuing population surveys to determine 

 mule deer population characteristics and trends in relation 

 to range conditions through the early 1970s (Mackie 1973). 

 A marked decline in mule deer populations and low fawn 

 recruitment despite seemingly favorable range conditions 

 during 1973-1975 brought support for intensive studies of 

 population ecology and factors regulating deer populations on 

 the area during 1975-1987. 



Our first priority was to provide knowledge for 

 management of mule deer in "breaks" habitat. However, the 

 results also may be important from a more theoretical point 

 of view. Few, if any, serious ecologists would deny that 

 existing knowledge of population ecology has many 

 shortcomings. Despite myriad theoretical, experimental, and 

 field studies, questions and confusion about pattern and 

 process in population organization, population-habitat 

 relationships, and population dynamics and regulation persist. 

 Reasonably accurate long-term data on population ecology of 

 deer and other large mammals are rare. Thus, Caughley (1980) 

 notes that, aside from McCullough's (1979) study of 

 white-tailed deer in the George Reserve, Sinclair's (1977) 

 study of African Buffalo, the long-term studies of moose and 

 wolves on Isle Royale, and the work of Laws and his associates 



