210 The Ruffed Grouse 



best all-use cover for grouse. Apparently it may also serve a like 

 purpose for some predatory animals, and in any event they would 

 tend to hunt wherever their prey is most plentiful. Least hazardous 

 are coniferous woods and overgrown lands, including thickets. 

 The usual concept of safe cover, therefore, seems to hold for ruffed 

 grouse. However, it must be remembered that factors that benefit 

 grouse, such as escape cover, are effective only for populations 

 well accommodated by the environment ( that is, below the thresh- 

 old of security ) . 



PREDATORS AS AN AGENT OF SANITATION 



It is generally recognized that predators take the prey that is easi- 

 est to get— limited, of course, by the range of their food habits. This 

 being the case, it is reasoned that sick, injured, and weak individuals 

 of a prey species will be the first to succumb, other things being 

 equal. Thus the predator acts to maintain or increase the virility of 

 its prey species. Likewise, many predators are also scavengers to a 

 degree. They clean the range of dead animals that escaped attack 

 before dying from some cause other than predation. How do these 

 ideas stand analysis with respect to grouse? 



The ruffed grouse normally maintains its full vitality in the face 

 of affliction until very near death. By the time a bird shows weak- 

 ness of flight, or sluggishness of activity, it is ordinarily very near 

 death. The time during which a predator might take a sick grouse 

 easier than a well one is very limited. Although not very significant, 

 the sanitation principle probably does hold with grouse within this 

 limitation. Probably of greater significance than physical weakness, 

 is the vulnerability of birds that are in unfamiliar habitat. Similarly, 

 grouse living under strain of intolerance by confreres may fall vic- 

 tim to an enemy more readily than would otherwise have been the 

 case. 



When it comes to cleaning up carcasses of birds that have met 

 death through means other than enemy attack, the scavengers are 

 very efiicient. For example, three birds that were shot and left lying 

 without being handled by man, were taken the first, second, and 

 fourth nights of exposure. It is rare indeed for a grouse to lie on the 

 ground long enough for the flesh to rot appreciably. 



