Productivity and Populations 279 



An increase of ninety-three per cent from breeding stock took 

 place in 1930 with Httle reduction the following winter, leaving a 

 net increase of fifty-seven per cent in the spring of 1931. The seasons 

 of 1931 and 1932 also had high productivity, one hundred nine per 

 cent and one hundred twenty per cent respectively, but owing to 

 mounting winter losses the net yearly gains in breeding population 

 dropped to fifty-three per cent in 1932 and to only twenty-six per 

 cent in 1933. The forces of decimation were catching up, both preda- 

 tion and disease having increased notably. Then productivity in 

 1933 fell way off owing to a very high brood mortality of unknown 

 cause, resulting in a summer increase of only eighteen per cent of 

 the spring population. This was followed by a thirty-seven per cent 

 winter loss which, while somewhat lower both in number of birds 

 and percentage of September population than that of the previous 

 year, resulted for the first time in a reduction in breeding stock, 

 amounting to a twenty-six per cent net loss for the year. 



Table 9 



Population Changes on 2,304 Acres of Grouse Cover, 

 Connecticut Hill Area- 1929- 1938 ^ 



'^ Figures taken from Edminster (1938) and derived from data in N. Y. S. Cons. 

 Dept. Ann. Reports, 1930-38. 



2 1933 figures calculated from sample data. 



Recovery in 1934 reached a high rate again with a productivity 

 of one hundred twenty-five per cent, the highest noted in any year 

 except 1938. This brought the fall population nearly up to the high 

 level of 1932. A normal winter loss (42 per cent) for a dense popu- 



