A very large percentage of the birds described in the present volume are migratory, although the seasonal movements of many of the species cannot be remarked, to any great extent, by the wanderer along the coast. Such thoroughly aquatic species as the Auks, the Petrels, the Divers, and the Grebes, move south or north, according to season, some distance from the land; and it is often only by the chance of rough weather driving these birds near to the land, that we are enabled to learn that their migrations are in progress, or that certain species have once more returned to our area for their winter or summer sojourn therein. The Ducks, Geese, and Swans, are birds of migratory habits, and in certain localities much of their seasonal movements may be observed from the shore. Then, again, the Gulls and Terns, although often migrating some distance from the land, may not unfrequently be seen passing up or down the coast on passage. This is especially the case with the Black-headed Gull, and the various species of Terns. These latter birds are often seen, in spring and autumn, in flocks of varying size, flying north or south, close inshore, fishing as they go, sometimes remaining a day here or there, where food chances to be plentiful. The migrations of certain species of land birds that reside in littoral districts are also pronounced and regular, and easily remarked along the coast; the arrival and departure of Martins and Swallows being a specially interesting feature. But the most remarkable birds of all, so far as concerns migration, are those to which our second chapter is devoted, viz., the Plovers and the Sandpipers. Perhaps in this group more than in any other, the habit of migration is most strongly displayed. The journeys some of these birds undertake in spring and autumn can only be described as marvellous. The Sanderling breeds in the North Polar Basin, and in winter is found in the Malay Archipelago, in the Cape Colony, and in Patagonia; the Knot has a similar distribution in summer, but in winter visits such enormously remote localities as Australia, New Zealand, the Cape Colony, and Brazil! Well may these little birds excite exceptional feelings of interest in the observer who watches them, each recurring season, running blithely over the sands and the mud-flats, when he remembers the distances they travel.