REGULATION OF THE GROUSE HARVEST 



677 



neither occur frequerjtly nor do they usually maintain themselves as such for long, at least in 

 the Northeast. The proportion available for harvest, then, is normally something less than the 

 total increment. Theoretically, as the density approaches the maximum number of birds a 

 covert will hold, an increased proportion of the birds may be harvested. 



But in actual practice the carrying capacity for many habitats is so low that, even when 

 well stocked (for such coverts), few or no birds may be taken by man without running the 

 risk of reducing the total population to a point where maintenance of the seed stock is 

 endangered. Just where this point lies has not been accurately determined. It is certainly 

 dangerous, however, to reduce the numbers over a sizeable area below one bird to 30 acres 

 of grouse habitat. 



If it were possible to determine accurately the carrying capacity of individual grouse 

 coverts, as well as the degree to which the fall poj)ulation approached or exceeded that 

 figure, one could then closely estimate the number of grouse available for harvest by the 

 hunter and still leave a reasonable seed stock. Rut the ability of an area to support grouse 

 changes, even from year to year, with the weather, with ])redator-buffer relationships, and 

 with cover succession. Furthermore, the cost of detailed censuses is prohibitive except on 

 relatively small areas. 



Thus a more practical, if less exact, method is here suggested. Its basis lies in part on 



100 

 liJ 



UJ75 

 CO 



I 



Q 



50 



I- 

 Z 

 UJ on 



a. 



UJ 



100 



5 10 15 20 25 30 35 40 45 50 55 60 



FALL POPULATION DENSITY Cbirds PER lOO acres) 



u 



FIGURE 70. APPROXIMATE MAXIMUM ALLOWABLE HARVEST BY HUNTING ACCORDING TO 



DENSITY OF FALL POPULATION 



measurements of grouse productivity* made during the Investigation, in part on that inde- 

 finable product of experience called ''grouse sense". In utilizing data from the study areas 

 it has been necessary to make certain assumptions and judgments. The accompanying chart 

 must, therefore, be regarded as the best interpretation the authors have been able to make 



« See Chapter XU. 



