112 



COVER CHARACTERISTICS AND SHELTER REQUIREMENTS 



tions, since use, too, is often inversely proportional to the distance from the type edge. For 

 instance, a study of the use made of blocks of coniferous reforestation* indicated that birds 

 seldom penetrated much beyond 200 feet inside the block. Likewise, large, overgrown fields 

 are seldom patronized much by grouse except where an edge adjoins wooded cover. 



One cannot, however, carry this idea to extremes. Each type fulfills a function in providing 

 certain necessities. In general those that provide food (overgrown lands and cut-over areas) 

 may well be small and scattered. Those furnishing shelter at critical periods (particularly in 

 winter and during the spring breeding season) meet grouse requirements better if they are 

 somewhat more extensive. 



GROUSE ARE SELDOM ABUNDANT WHERE THE FORESTS ARE EXTENSIVE AND UNBROKEN 



Much of the foregoing discussion is also equally applicable in considering the shape of a 

 type. In general, the larger the "edge" the more productive the type, for the opportunity for 

 grouse to make use of it is thereby increased. Irregularly shaped pieces are both desirable 

 and the rule, though extremes may result in lowered use'''. 



Type Composition 



The vegetative makeup of a type is determined by climate, soil, slope, accidents such as fire, 

 by the life within it and by man's activities. Grouse cover needs are best met by vegetation 

 characteristic of the intermediate stages in plant succession from open land to climax forest. 



* Described on p. 174. 



A See Chapt, XIV. "Deeisniog Croute HsbiUti" for tuggested type pattern. 



