178 The Ruffed Grouse 



buds are always available above the snow, and the grouse turn 

 largely to them for food when snow is deep. 



What then, if sleet or freezing rain puts a coating of ice upon all 

 vegetation? This condition probably renders completely unavailable 

 foods under the snow. It may make budding difficult but probably 

 does not entirely prevent it. Even if the ice coating is complete 

 enough and thick enough to prevent feeding by grouse, it seldom 

 lasts long enough to cause starvation of the birds. It is normal for 

 grouse to refrain from eating for a day or two during bad storms 

 anyway. The fact that not a single normally healthy^ grouse has 

 been known to die of starvation is proof enough of the ability of the 

 species to forage satisfactorily under any winter conditions that 

 have been observed. 



If cold or wet early summer weather may be considered an emer- 

 gency, then we probably have one type of food emergency that 

 young grouse are sometimes unable to meet. This condition has 

 just been discussed. 



Competition of Other Species for Food: In considering the major 

 grouse food plants, notes were made concerning competition for 

 these foods with other forms of wild life. Most of the preferred foods 

 are also taken by other species in considerable amounts, but in only 

 a few cases does this noticeably affect the grouse. Even in these 

 few cases," only the local distribution of the birds is modified. Rarely, 

 if ever, is the number of grouse over a large area materially affected 

 by food competition. 



Maintenance of Grouse Health: Does the availability of certain 

 foods affect the health of grouse? More particularly, does the relative 

 lack of fruits and green leaves in late winter in the northern range 

 and the resulting dependence on a bud diet so affect the bodily 

 health of the birds that their breeding-season vigor is impaired? If 

 that were true, would it result in weakened young birds the fol- 

 lowing spring or summer? Does the quality of certain types of im- 

 portant foods used in winter and early spring, such as buds, vary 

 in different years in a manner that affects the health of the birds in 

 the spring, resulting in weakened offspring? Conceivably the chemi- 

 cal content of tree leaf buds, possibly in regard to the representa- 



^ We have observed cases of stanation in birds with injuries to their digestive 

 system. 



2 Swanson (1942) notes that grouse are never abundant in an overbrowsed deer 

 yard due to the destruction by deer of important grouse food plants. 



