T. A. Coward

“ I have seen bands trailing south in autumn in which all the birds were immature, and others in which a number of young were accompanied by a few mature birds; though, certainly, these old birds did not appear to lead. Another assertion, that the old and young do not even travel by the same route rather supports the idea that the young birds find their way simply by a sense of direction, a sense liable to blunder; whilst the old birds travel by the perfected or best route which their experience has taught them. Martorelli wisely asserts that orientation is not infallible. but develops with age. ”

“ There is a very generally accepted idea that birds prefer to travel with the Wind striking them diagonally—the "beam-wind theory," a theory, which so for as I can see, has absolutely no sound foundation. When on the Kentish Knock Lightship, Mr Eagle Clarke noticed, on a bad day, east to west migrants hurrying past "as if to avoid as much as possible the effects of the high-beam wind." ”

“ Mr A. H. Clark worked out the long oversea and overland course followed by the American golden plover, and showed to his own satisfaction that the birds always travelled at right angles to the prevailing winds; therefore, he argued, they were guided by the beam-winds; always keeping the wind on their flanks led them aright (14) . He says that if they fly at 100 miles per hour, with a beam-wind of 30 miles per hour, they will reach a spot 100 miles from whence they started, but 30 miles to leeward of a line drawn at right angles to the wind. ”

“ Certain species summer in Greenland either in the same areas or in areas comparatively near to one, another; some of these travel in autumn south-east, and winter in Europe or Africa, and others go south-west into the States or South America. Most of these are distinctly eastern or western forms, but occasionally American birds are met with in Europe, and European in America. Probably at the start these stragglers joined the wrong band, and travelled for company and unconsciously by the wrong route. Birds drifted to leeward may find companions of quite an alien tribe ”

“ We can afford to put aside as purely speculative Middendorf's suggestion that the bird is impelled or dragged by magnetic force, but we cannot deny that it uses its eyes and that it has a wonderful memory ”