up to the end of July, not very far from where it was hatched out. Then, again, it is difficult to explain how on a large moor the young birds have departed before they are capable of sustained flight, especially if none of the neighbouring moors have received any noticeable addition to their stock. Lastly, it is permissible to ask how is it that when the young birds emigrated to more congenial surroundings they omitted to take their parents with them? Each of these points presents a difficulty, and the combination of them renders the migration theory untenable as an explanation for the absence of birds at any time up to the beginning of August.[1]
Another favourite theory is that all the young birds have been drowned, and if it so happens that there has been a severe thunderstorm in Drowning June the theory becomes a certainty — though not a single drowned chick may have been found on the moor.
There is no doubt that many young Grouse are destroyed by drowning, either as a result of being caught in a drain by a heavy shower, or by the flooding of low-lying ground. It is difficult to estimate the loss Sheep
drains occasioned by drowning in sheep drains, owing to the extreme difficulty of detecting the small corpses in the swollen stream. One of the Committee's correspondents, a gamekeeper, who makes it a rule to inspect all the drains upon his ground several times during the nesting season, states that on one occasion only has he found a drowned chick in a drain. This evidence is, of course, only negative, and against it has to be reckoned the fact that many observers have spoken definitely as to the damage arising from this cause. On many moors the sheep drains have been scoured by floods into deep chasms, from which it would be difficult for the chick to emerge on the approach of danger, and any one who has seen a hill drain immediately after heavy rain, when it is running bank high in a miniature torrent, can picture the risk which might attend any attempt on the part of the mother bird to lead her brood over the obstacle. Much may be done to minimise this risk by forming little backwaters in the drains with shelving banks, by which the young Grouse may escape in time of danger. With regard to flooding, it is necessary to speak with more reserve. Flooding is a gradual process, and the instinct of self-preservation, which teaches the young Grouse to Flooding hide from his foes, will doubtless also teach him to retreat before the rising waters. In one case, however, flooding is a real menace, for if the
- ↑ Vide vol. ii. Appendix G.
