FOOD AVAILABILITY AND SHORTAGES 229 



dangerous one and should be used with caution and then only by experienced operators. This 

 item is considered in detail in Chapter XVI. 



FOOD AVAILABILITY AND SHORTAGES 



As has been noted, the list of plants patronized by grouse in New York alone includes 

 994 items. So widely distributed and commonly found over much of the State are many of 

 these that there are few grouse habitats without a comparatively large native supply of food- 

 producing plants. 



Because a plant is present, it does not always mean it is producing grouse food, for some 

 do not fruit or seed except under favorable conditions. Most of the food plants are primarily 

 pioneer or transition species which do best in the sunlight along woods edges, in overgrown 

 lands, in cut-over areas or in blow-downs. Insects also are most abundant in well-lighted 

 places where the vegetation is varied and lush. Grouse might not starve if they were confined 

 exclusively to heavy woodlands, but they would not find there a majority of the foods they 

 like best. 



So long as the territory of an individual grouse includes openings, whether made by man or 

 Nature, that foster the pioneer and transitional food species, these may usually be depended 

 upon to produce a sequence of foods which me?t the birds' needs throughout the year unless 

 grazing or cultivation intervenes. Of course la'k of handy and suflicient shelter may make the 

 food largely unavailable, for both cover and food must be present and adequately inter- 

 spersed to make a grouse habitat productive. 



There is no evidence that grouse have ever starved to death in the Northeast. The weights 

 of adults collected in numbers throughout every month of the year show relatively slight 

 variations. These can be explained in part on the basis of seasonal activity, in part by the 

 less adequate nutritional character of their winter and early spring diet. Even the heaviest 

 sleet storm does not armor buds and twigs long enough to produce a serious food shortage. 

 Grouse held without food fail much more rapidly than do pheasants or quail. A period of from 

 three to four foodless davs under winter conditions produced an average loss of 22 per cent in 

 the weight of birds kept in captivity. They had eaten only natural foods during the preceding 

 weeks. Experiments* indicate that grouse have very little metabolic or chemical reserves fri>ni 

 which to endure much longer periods without food. 



Whether they suffer from shortages of certain nutrients one cannot sa>. Helati\eU little 

 is known as to the chemical composition of grouse diet and nothing as to the degree of physi- 

 ological availability of the nutrients in their foods. Scientific studies of game bird nutrition, 

 as yet in their infancy, must await the production of a large number of grouse in captivity, 

 as well as improvement in techniques for handling them. In the meantime, in summary food 

 items known to be taken by grouse in large quantities are available in large amounts 

 throughout the year in every inhabited grouse cover known to the Investigation. No starved 

 birds have ever been found. No sharp weight losses have been recorded even in adverse 

 weather. Food shortages in the generally accepted sense are believed, therefore, not to occur. 



A few of the more abstract relationships of food to health are pointed out later in the 

 chapter. 



EFFECT OF FOOD ON GROUSE DISTRIBUTION 



At some seasons grouse exhibit a marked preference for coverts where certain foods are 

 easily obtained. Curiously enough this is most evident in the summer and fall when food is 



* Set- Appoiicliv, p. 7(il. 



