density-dependent regulation are shorter than 7 years. Only 

 recently have studies of adequate length been available that 

 properly question existing concepts. 



In the Breaks environment, the physical condition of 

 females declined with age and following several years of above 

 average recruitment rates, regardless of forage conditions. 

 We found no evidence that intraspecif ic competition for forage 

 played a major role in that condition cycle. Reduced initial 

 reproductive effort and poor survival of the subsequent fawn 

 crop often go hand-in-hand because of the female condition 

 cycle and because, on average, poor forage years tend to 

 follow good forage years. Obviously, those females attempting 

 to recruit fawns during periods of poor forage conditions will 

 be in worse physical condition than during times of good 

 forage conditions, but body condition for productive females 

 declines even during good forage years if they rear fawns. On 

 the other hand, females that do not rear fawns and do not 

 undergo lactation stress can maintain and often even improve 

 body condition during relatively poor forage years. The 

 length of winter through its effect on plant dormancy and the 

 severity of winter through its effect on energy expenditure 

 also affected deer condition and the interaction of 

 reproduction and mortality. 



r = 0.93 



400 500 600 700 800 900 1000 



Total Number of Deer - December 



1100 



Figure 11.2 



Fawns observed per 100 females during December 

 plotted against the total number of mule deer 

 in the population during December, 1973-1979. 



315 



