rHo_- breed. og failure 

 ^ infertile 



deod Qeror-»& 



174 

 Breeders 



STABLE POPULATION 



175 



FIGURE 53. AVERAGE LIFE EQIATION OF STABLE GROUSE POPULATION 



/ 



FIGURE 54. AVERAGE LIFE EQUATION OK (.KOI >L I'OPl LATION DEGREASIM, PRIMARILY AS A 

 RESULT OF HIGH OVERWINTER MORTALITY 



