94 THE GROUSE IN HEALTH AND IN DISEASE 



December to March, between 3 P.M. and 6 P.M., is 250 

 grains, whereas the average weight of food found in a Grouse 

 crop from April to November, between 3 P.M. and 6 P.M., 

 is only 50 grains. 



The fact that more food is required in winter to maintain 

 the body temperature would, of course, partly account for this 

 increase, even if the heather had the same food-value. But as 

 heather certainly has an inferior food- value in winter, the amount 

 taken must be increased in a far greater proportion. No doubt 

 the necessity for provision during the longer hours of night- 

 time has some effect in the overfilling of the crop in winter, 

 but this would not account for crops being heavier in March, 

 when the days are comparatively long, than in November 

 when they are short. 



The interesting fact remains, and is amply proved by the 

 figures, that more food is required by the Grouse in winter 

 than in other seasons of the year ; and as in winter the pro- 

 portion of Calluna to all other foods is as seven to one, it is 

 obvious that a very great advantage accrues to a Grouse on a 

 moor in which young and comparatively nourishing heather 

 is abundant during the winter months, i.e., on a well-burned 

 moor, well covered with short close heather of a varying number 

 of season's growth. 



To put this conclusion in other words ; whereas in summer 

 a certain area of heather will support a bird comfortably, many 

 times this area will be required for the same bird in winter, 

 so that the capacity of a moor, as regards the question of stock, 

 must be gauged mainly by its Grouse-feeding value during the 

 winter months. 



If we consider this generalisation with reference to moor 

 management we shall see that a moor carrying its full tale of 

 birds in the summer becomes automatically and unavoidably 

 overstocked in the winter unless the stock is heavily reduced 

 by shooting, for not only is there less food available, but the 

 birds require a much larger quantity of food to keep them in 

 health. 



