Productivity and Populations 297 



1936. All were continuous forest. They are consistent in showing 

 the highest spring densities in 1933 with a marked decline in 1934. 

 In only one of three of the areas observed in 1936 had the popula- 

 tion regained its 1933 level. Maximum spring densities recorded by 

 Fisher for various areas were six and five-tenths, nine and two-tenths, 

 fifteen and two-tenths and fifty-three and three-tenths acres per 

 grouse; minimum spring densities on these same areas, in order, were 

 thirty-three and six-tenths, twenty-two and one-tenth, two hundred 

 thirteen, and one hundred twenty-eight. Here it appears that grouse 

 densities were higher tlian those of the Adirondack New York area, 

 but lower than those of Connecticut Hill. The September peak 

 season densities for these areas indicates a greater maximum sum- 

 mer productivity than for any New York areas. These maxima were: 

 two and seven-tenths, three and five-tenths, four and seven-tenths, 

 four and eight-tenths and seven and three-tenths acres per grouse; 

 minimum peak season densities on these same areas, in order, were 

 nine and seven-tenths, eight and nine-tenths, twenty-one and three- 

 tenths, fifty-eight and two-tenths, and eight and seven-tenths acres 

 per grouse. These high densities were never repeated two years in 

 succession; in fact, on all but one of Fisher's areas, a very high den- 

 sity level was reached only once in the period involved. This in- 

 dicates greater variability in peak populations than observed in 

 New York. 



King ( 1937 ) reported on April and October populations of grouse 

 on an area of forest in Minnesota for the years 1927-36. The maxi- 

 mum spring breeding densities, four acres per grouse, were notably 

 higher than any New York areas achieved, although comparable 

 with many individual cover unit records. The high density period 

 extended three years from 1932 to 1934, increasing gradually from 

 a spring density of forty-two and eight-tenths acres per grouse in 

 1927 to the maximum and dropping back to twenty-six and one-tenth 

 acres per grouse in 1936. 



The October grouse densities in King's area show much greater 

 range of variation than I have experienced. The maximum density 

 reached two and six-tenths acres per grouse in 1933. A decline to a 

 low of thirty-three and six-tenths acres per grouse took place by 

 1936. These records support the conclusion that grouse populations 

 fluctuate more widely in continuous cover regions than in discon- 

 nected cover. 



