366 



REPRODUCTIVE CAPACITY OF THE SPECIES 



TABLE 54. EMBRYO MORTALITY IN FIRST NESTS AND IN RENESTS— 



ENTIRE STATE— 1931-1941 



Firet nests 



Renesta 



*Calculated in relation to total fertile eggs. 



Upon examination of the egg viability records for all sections of tlie State, it was at once 

 apparent that only one group failed to follow the general trend. Connecticut Hill nests had a 

 consistently higher loss and for this reason are listed separately in table 54. 



The explanation for this discrepancy in the Connecticut Hill nests apparently lies with the 

 Investigation workers and not with the grouse. From the time when first located, these nests 

 were observed once each week until hatched. In spite of special precautions taken, some of 

 the birds were disturbed and flushed several times. This disturbance seems to have resulted 

 in some additional inadequacy of incubation beyond that usually recorded. 



On the other hand, most of the nests found over the State were not disturbed after discovery. 

 The final record was made after the hatching date had passed. 



Because of this disturbing factor, the state wide data, excluding Connecticut Hill, are more 

 typical than the records as a whole. This group exhibits a notably narrow range of varia- 

 tion in embryo mortality fron year to year. Among the first nests these losses ranged from 

 zero in 1939 to 3 per cent in 1937. The 11-year average loss was 1.3 per cent. 



For renests, the upper extreme and average were both greater. The highest loss was 8.9 

 per cent, occurring in 1932. The number of observations of renests each year was rather low 

 and hence the larger losses observed in the embryos may be somewhat exaggerated. However, 

 the average loss of 3. .5 per cent of fertile eggs is derived from quite adequate data and, there- 

 fore, some diHercnce appears valid. 



