Exceptionally heavy harvest of adult females and fawns in 

 connection with low overall fawn recruitment in 1961-62 

 resulted in a sharp, though relatively modest population 

 decrease to winter, spring, and summer 1962. Despite a 

 subsequent reduction in the harvest, continued low recruitment 

 resulted in stabilization of population size to the following 

 winter-spring and provided the base for population increase 

 and a larger "surplus" in 1963 when good recruitment occurred. 



The combined effects of low fawn recruitment, severe 

 winter mortality, high overwinter mortality of adult females, 

 and relatively high harvest mortality of adult females 

 resulted in a very sharp and substantial decrease in both 

 total population size and the adult female population from 

 autumn 1971 to spring and summer 1972. Continued liberal 

 harvests of adult females along with low fawn recruitment 

 influenced further reductions in total population and adult 

 females through 1974. Overwinter mortality of adult females 

 was relatively low (5-10%) in each of those 3 years. However 

 low recruitment and a female age structure comprised primarily 

 of individuals with a very low natural mortality rate 

 (susceptible females were eliminated during the severe 1971-72 

 winter), essentially precluded any "harvestable surplus" 

 throughout the period. Under those circumstances, all 

 mortality was "additive" and reduced the female population. 

 Such a low population level was reached that the absolute 

 number of fawns recruited was insufficient to stabilize or 

 increase population size. It was not until 1978, when fawn 

 recruitment increased as a result of decreased coyote 

 predation, that the population could begin to recover. 



The potential for a similar impact of hunting existed 

 during 1964-1965, when severe winter conditions also occurred. 

 Although fawn mortality was heavy during the 1964-65 winter, 

 adult female mortality was relatively low. Harvest mortality 

 of adult females was also relatively low in autumn 1964. 

 Thus, while total deer numbers on the area declined 

 considerably to spring 1965, the decrease in adult female 

 numbers was not extreme. Also, fawn recruitment exceeded 

 adult female harvest rates and was only slightly below total 

 female mortality in 1965 and 1966 so total female numbers 

 remained relatively high and stable until fawn recruitment 

 increased sharply in 1967. 



Generally, in this environment, conditions that resulted 

 in below-average fawn recruitment rates also resulted in 

 above-average natural mortality rates among adult females, and 

 vice versa. When recruitment rate is declining and female 

 mortality is increasing, and a management goal is to stabilize 

 or increase numbers of deer, the only option is to curtail 

 hunting mortality of adult females as rapidly as possible. 

 Previously, it was assumed that recruitment was declining and 



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