at the end of 7 years. Coincidentally , this is also an 

 average annual growth rate of r=0.50, equivalent to the 

 maximum expected for the population (see Chapter 4). By 

 additional "modeling," we can compare the relative 

 contribution of each of several major mortality factors in 

 limiting population growth from the potential to that actually 

 realized. 



If no emigration of yearling females had taken place 

 during 1980-1987, but all other mortality factors had operated 

 at rates observed annually, the mule deer population would 

 have been 1,725 in December 1987 (1.23 times greater). If 

 reproduction had occurred each year at the maximum observed 

 rate, but all mortality factors had remained as observed, the 

 population would have reached 1,780 deer in 1987 (1.27 times 

 greater) . Similarly, assuming that all other mortality 

 factors operated at observed rates, if there had been no 

 hunting mortality of antlerless deer, the population would 

 have reached 2,155 deer in December 1987 (1.53 times greater). 

 With no hunting of any deer, it could have reached 2,940 (2.09 

 times greater) . With no coyote predation on any deer, it 

 should have reached 9,540. Although coyote predation was the 

 proximal cause of loss of most of the potential, and in its 

 absence the population could have been 6.8 times higher in 

 1987 than actually observed, the interaction of all factors 

 was even more important. Without all factors interacting, the 

 population would have been 27.6 times higher than actually 

 occurred. 



Obviously, all other mortality rates would not have 

 remained the same if any factor had been eliminated. The 

 elimination of even the factor with the least influence, 

 emigration, would have resulted in higher populations in 

 December than we ever observed on the area. Thus, results 

 equivalent to "penned" deer studies may have occurred, and at 

 higher population levels, we may have observed density-related 

 effects on reproduction and mortality. The important 

 implication is that the combination of all factors (multi- 

 factorial approach, Lidicker 1988) apparently has kept the 

 population below levels where density-dependent mortality is 

 easily observable. Probably, no 1 factor can be said to 

 regulate the population unless we call the total variable 

 environment 1 factor. 



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