THE FOOD OF THE RED GROUSE 95 



Migration of birds in winter obviously complicates the 

 question. In the case of a moor on high ground, which often 

 loses all its birds in winter, probably natural conditions regulate 

 the stock of birds automatically during spring and summer. 

 But on the adjacent low-lying moors the case is more serious ; 

 for the ground has to supply not only more food than is needed 

 for its own stock in summer, but in addition an increased 

 seasonal demand made upon it during the winter months by 

 hundreds of undesirable immigrants from the higher ground. 

 Such low - lying moors must always run the risk of being 

 dangerously overstocked in the winter. 



In certain parts of the country oats form a regular seasonal Oats, 

 change in the dietary of Grouse, and this form of food must 

 now be considered. 1 



Very few birds with corn in any part of the alimentary 

 canal were submitted for examination ; but so far as these 

 specimens show, oats are an unsuitable form of food for Grouse. 

 As is well known, Grouse often visit the stubbles and corn 

 stocks in very large packs in the autumn in September, October, 

 or November, according to the season and locality. They 

 seem to know that they are out of place, and finding themselves 

 with a wealth of food all round, away from their normal surround- 

 ings, are eager to fill themselves as full as possible in a very 

 short space of time, aware, by instinct or experience, that 

 they may be disturbed at any moment. One consequence is, 

 as the examination of birds has shown, that they eat as much 

 husk as grain,, instead of picking and choosing, as Partridges do, 

 in a quiet and leisurely manner. This difference in the crops 

 of Grouse and Partridges that have been feeding on the same 

 ground is very noticeable. The one is filled to repletion with 

 indigestible and exceedingly irritating husks and a compara- 

 tively small amount of grain, while the other (the Partridge's 

 crop) contains grain only. 



The result in the Grouse is that the whole alimentary canal, 

 from one end to the other, is soon in an irritable and inflamed 



1 Vide also chap. i. p. 29, and chap. iv. pp. 145 et seq. 



