strong density-dependent relationship apparent when a 1 year 

 lag in yield was plotted against deer numbers (Fig. 5.21) or 

 when yield was plotted against numbers of females rather than 

 numbers of adults. 



It is apparent from the empirical data that deer density 

 was not a reliable predictor of recruitment rates, survival 

 rates, or yield for this population. Although some density 

 relationships may exist, apparently the variability of other 

 influencing factors ( second-order effects , cf. Caughley 1981b) 

 most often override potential density effects. 



600-n 



<J 500 

 § o) 400 



CO r- 

 LL .E 



(f) 



300- 



0) T3 

 .Q <D 

 C ~ 200 



|2 



Z o 

 £ 100 





„ *■ 



-t f— I— 



200 



400 600 800 1000 



Number of Adults - Spring (Nt) 



1200 



Figure 5.21 



Yield in number fawns recruited to 31 May 

 plotted against the number of adults in the 

 population on 1 June, 2 years prior to fawn 

 recruitment. The dashed line represents the 

 yield curve assuming complete linear density- 

 dependent survival . 



155 



