Food and Water 177 



This may not be true everywhere in the range of the niJBFed grouse 

 but is generally true in the Northeast. 



That the supply of food is a possible limiting factor in areas that 

 are well stocked with grouse is conceivable although not likely. Let 

 us consider this prospect under some of the most likely conditions. 



Food Shortages: A shortage of food for adults at any time of the 

 year except winter and early spring, or for chicks except during 

 the first six weeks of life is altogether unlikely. So far as fruits, seeds, 

 and succulent leaves are concerned, a drastic food shortage in late 

 Mdnter and early spring is conceivable. A lack of buds of hardwood 

 trees and shrubs, however, is out of the question. As grouse are well 

 able to thrive for considerable periods on a diet of buds, we can rule 

 out shortage of foods for the adult as a limiting factor on the usual 

 grouse range. 



A shortage of insects in June or early July, at which time they are a 

 vitally necessary food for the young bird, would be disastrous. Nor- 

 mally, grouse coverts contain from one hundred to five hundred 

 thousand insects and other arthropods per acre at this time of year 

 in the zone from the loose ground litter to a height of one foot above 

 ground, the area of availability to young grouse (estimates from 

 measurements taken on Connecticut Hill ) . Variation in normal years 

 depends upon the cover type and the weather. While we have not 

 measured the insect populations in severely abnormal seasons, we do 

 know enough about the effect upon them of exceedingly cold and 

 wet weather to surmise the possible consequences to young grouse. 

 Shortage of animal food during seasons of cold, or cold and wet 

 from mid-May to the end of June is one of the likely contributing 

 causes of excessive juvenile mortality that often precede years of 

 greatly decreased grouse numbers ( see effects of weather on grouse. 

 Chapter VI ) . The question as to whether these losses in young birds 

 occur primarily as a result of food shortage or directly from the cold 

 is not clear. Surely the two factors sometimes combine to take a 

 heavy toll. 



Availability during Emergencies: We have already pointed out 

 that foods provided by low-growing vegetation, mainly leaves, fruits, 

 and seeds, may be completely covered with snow for considerable 

 periods in the winter. These, then, are relatively inaccessible al- 

 though the birds are surprisingly able in seeking them out. But tree 



