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 proportion 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 young heather of a varying number of seasons' 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 the 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.
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 Effect of
migration.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 change in the dietary of Grouse, and this form of food must now be considered.[1] Oats.
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
