on elephants in east Africa, "most of the other studies that 

 have been done coalesce into an amorphous mass of nothing 

 much. " 



We believe our data set is sufficiently complete and 

 accurate to show not only what the mule deer population has 

 done, but why, and to address broader questions relating to 

 issues such as carrying capacity, population regulation, yield 

 theory, predation, and habitat selection. Perhaps somewhat 

 more specifically, we can also address the extent to which 

 "...the principles derived [from studies of white-tailed deer 

 on the Edwin S. George Reserve in southeastern Michigan] are 

 general and should apply to most large, long-lived mammals — in 

 modern ecological parlance, K-selected species" (McCullough 

 1979) . 



We also attempted to answer age-old questions about 

 population regulation. What determines the size of a 

 population? Why do certain numbers occur at one time and 

 place and other numbers at different times and places? The 

 mule deer population we studied did not increase without limit 

 nor did it decline to extinction. Yet, population regulation 

 in its traditional sense is not a proper phrase for the 

 dynamics we observed. Our results and conclusions concern 

 population ecology and all its attendant interrelationships. 

 The total environment of the population and its inherent 

 heterogeneity and dynamics must be considered to understand 

 population dynamics. We concur with Ratcliffe (1958) that 

 animals in a population cannot be regarded simply as l/N. 

 Individual differences in animals and the heterogeneity of 

 their common and individual environment in time and space are 

 all important elements of population ecology and "regulation". 



General Theories of Population Regulation 



Ecological literature of the last 50 years is replete 

 with books and articles by proponents of various theories of 

 population regulation. These include many syntheses, 

 reinterpretations, and reviews (e.g. Milne 1957, Krebs 1972, 

 and Murray 1979). Because no one theory or school of thought 

 has been universally accepted as yet, a brief review of 

 previous and current theories of population regulation, 

 generally and among ungulates, is necessary to place our study 

 and conclusions in perspective. 



The primary problem or question related to population 

 dynamics and regulation that theorists and empiricists have 

 tried to answer is composed of 2 parts. Krebs (1972: p. 269) 

 pointed this out when he stated: "One can make two 

 fundamental observations about populations of any plant or 

 animal. The first is that abundance varies from place to 

 place . . . The second observation is that no population goes 



