The further question naturally may be asked, "But why should they not fly in over the cliff tops?" We think there are already many reasons stated in our previous remarks why such is less likely to happen, during normal migration, whether by day or by night, and that they should avoid obstacles, and choose an easier if not a shorter route.
The population of these interior parts, which are bounded by precipitous coast-lines, appears to us almost certainly to arrive by the innumerable veins--if I may so call them--which run into and join the main arteries,--and thus a circular migration is evinced.
Birds in normal migration against a beam wind fly low, and on reaching low-lying sea-board pass on inland without resting. But on approaching high land, say 200 or 300 feet in height, while at night the greatest darkness is ahead of them, and the greatest light to the north or south of their course; during the day-time, if the wind is off-shore--a beam wind,--on approaching the lee shore, they enter upon a calm belt of sheltered air and water, and choose the easier path along shore. According to whether the off-shore wind is strong or light, will they approach nearer or keep further out; and, skirting the coast-line, so enter upon one of the great open highways of normal migration. This, which appears almost undoubted, will in great measure account for the invariably slender returns sent in by nearly all the rock-bound stations of the more precipitous portions of the Scottish Coast.
Regarding the migration of Woodcock generally, the following notes may prove of some interest. These I culled from the note-books and game register of a naval friend stationed at Corfu and the Albanian coast in 1879.
The first flight of Woodcock occurs about the first ten days of November, and it remains a very short time before passing on, unless abnormal "south winds keep them in cover." The second and heavy flight occurs about the middle of December, and may remain a mouth, and odd birds are shot even in February in the lower covers. Thomas Wood, Esq., British Consul at Patras,--an authority for the locality,--says that Woodcock come in November with a N.W. wind most freely, but in December with a N.E. wind.