300 The RiifFed Grouse 



here, intraspecific intolerance sometimes plays an important role in 

 determining the nimiher of birds accommodated. 



Using saturation point as the maximum density that the species 

 itself will tolerate ( a somewhat broader conception than that given 

 by Leopold ) , evidence shows this to be a bird to four acres. In every 

 case where tliis density was surpassed in the early fall, immediate 

 reaction set in in the fonn of dispersion and accelerated decimation. 

 On these well-populated coverts, carrying capacity was conditioned 

 by the action of this species characteristic. The maximum actual 

 carrying capacity exhibited by any covert observed (as measured 

 by winter survival) was four acres per bird of coverts exclusive of 

 open land. Areas like Connecticut Hill, taken as a whole, have a 

 carrying capacity of about eight to ten acres per bird. On a continu- 

 ous forest range like the Adirondack Mountains, it is about twenty 

 acres per bird. 



ENVIRONMENT AFFECTS PRODUCTIVITY 



We have observed that the actual productivity of a wild animal 

 like the ruffed grouse is far below the potential productivity. It was 

 noted that some of the inherent characteristics of the species are im- 

 portant in holding back the attainment of this potential; that its own 

 populations provide a check to its continued increase. We now con- 

 sider the other major limitation on productivity— the environment. 

 The environment is the physical world, organic and inorganic, in 

 which the grouse lives. It includes shelter, food, climate, and other 

 animals, including man— all the plants, animals, soils, and physiog- 

 raphy that make up its home and associates. 



It takes no imagination to appreciate the profound effects that the 

 environment exerts in reducing the numbers of any animal species. 

 They succumb from exposure and starvation, are eaten by preda- 

 ceous enemies, and waste away as a result of the actions of para- 

 sites or disease organisms. But just how important are these various 

 factors? How are they interrelated? 



Decimating Agencies. Most obvious factors are those agencies that 

 actually cause the death of grouse, either in the egg, immature, or 

 adult stages. The following discussion of grouse mortality is based 

 primarily upon the studies of the New York State Conservation De- 



