It is not generally recognized how important a part was played by birds in the guidance of early voyagers when sailing on the uncharted seas of the ancient world, and how their regular migrations year by year and season by season, along definite routes have contributed to the discovery of many lands and isolated islands. We know that Columbus made his first American landfall by noting the south-westerly direction taken by great flocks of small field-birds seen flying overhead in the evening towards land as yet out of sight of those aboard the ships; we know, too, that the significance of their flight was at once recognized, for did not Pinzon point out its meaning to his crew by his remark ‘Those birds know their business’ (Morison, 1841, 664-5)?

How true his words were we now know, for it is about the time of year (October) when Columbus saw these battalions of birds darkening the sky, that certain species of landbirds set out from the eastern shores of North America by a southerly route, via Bermuda, to seek a warmer climate and a more plentiful supply of food.