THE VALUE OF EDGES 



173 



blocks of forest cover; the rest represent "open" cover types usually of considerable size. 

 These of course also support edge vegetation and may in a sense be looked upon merely as 

 more extensive edges. 



On the other hand, type boundaries not apt to be characterized by edge vegetation such as 

 those between hardwoods and conifers, appear to influence the location of the nest little if 

 at all. 



Variation in Importance of Edges 



The attractiveness of an edge is dependent not alone upon its particular composition, hut 

 also on the makeup of the abutting types. This principle may be stated thus: the attractiveness 

 of an edge is inversely proportional to the extent to which the composition of the types that 

 border it approach the edge in composition characteristics. 



This idea is aptly illustrated by the nest studies just mentioned. 



Further evidence to indicate that the richness and variety of the vegetation within a type 

 may exert a strong influence on the use of the surrounding edges by both broods and adults 

 is clearly shown in plotting grouse contacts on the Adirondack study area (figure 15). 



ALCCn SWAMP 



HUOWOOOS 



HARDWOODS 

 a CONIFERS 



HARDWOODS 





CUT- OVER 

 (SLASHINGS! 



FIGURE 15. DISTRIBUTION OF ADULT GROUSE FLUSHES ON THE ADIRONDACK STUDY AREA 

 SEASONS, 1932-1941. each dot represents THREE FLUSHES 



ALL 



