We also know that population growth began during 1938 or 

 1939. Deer numbers increased progressively through 1947 or 

 1948, apparently reaching a population high that couldn't have 

 been much higher than 1500 deer based on both a reasonable 

 aerial strip census estimate plus 20% and practically 

 achievable population growth rates. The population increase 

 was probably halted by emigration of yearlings and mortality 

 during the severe winters of 1948-49 and 1949-50. 



Between 1938 and 1948, the population grew in a manner 

 similar to that illustrated (Fig. 4.7), regardless of the 

 degree of certainty about the number of years or deer 

 involved. Depending on the number of years involved (8-10) 

 and initial (25-100) and ultimate deer numbers (1200-1500), 

 the average instantaneous rate of growth for the deer 

 population was in a range of r=0 . 248-0 . 484 . 



Based on growth rates observed during 1960-1987, growth 

 rates in the projected range were achievable during 1938-1948, 

 although a sustained growth rate of 0.484 over 8 years was 

 unlikely. There was at least some hunting loss of adult males 

 during those years and at least a minimal amount of illegal 

 kill of all deer and natural mortality of adult females and 

 fawns must have occurred. Thus, we believe it is reasonable 

 to assume that the average instantaneous growth rate during 

 the period 1938-1947 was less than 0.484. The use of 50 deer 

 in 1938 for a starting point and 1500 deer in 1947 as the 

 population peak (Fig. 4.7) yields an average annual 

 instantaneous growth rate of r = 0.378, near the midpoint of 

 the potential range. 



Growth curve A (Fig. 4.7) represents an annual growth 

 rate of 0.378 between 1938 and 1947. It is unlikely that the 

 growth rate was precisely the same each year, so the shape of 

 the actual growth curve probably varied somewhat from that 

 plotted. An alternative growth curve (B, Fig. 4.7) assumed a 

 growth rate that decreased steadily with density (semi- 

 logistic) as observed by McCullough (1983) for white-tailed 

 deer on the George Reserve. That curve assumed a maximal 

 growth rate of 0.76 for the initial year, a decline to 0.50 

 the second year, and then progressive declines with density to 

 about 0.20 during 1946-47. Other alternative growth patterns 

 exist, but none deviate significantly from the general pattern 

 displayed in Figure 4.7. 



During the period 1938-1948, the population probably grew 

 in a manner similar to irruptive or introduced populations 

 (McCullough 1979 and 1983, Caughley 1970). Subsequent to 

 1948, the population fluctuated widely around what some might 

 call an "equilibrium density" of 3.8 deer/km 2 . The major body 

 of theoretical population work centers around the irruptive 



90 



