By many writers on ornithology, the Pied Wagtail has been regarded as a resident species in Great Britain, since it is to be met with in some parts of the country all the year round, but there can be no doubt that large numbers migrate southward for the winter, and return to our shores again in spring. On several occasions when crossing by steamer to the opposite coasts of France and Belgium, I have seen Pied Wagtails passing across and at times even alighting on board the vessel for a short rest.

On quitting the ship they would fly round and round for some seconds with their peculiar undulatory flight, and finally make off for the land in a straight line, often directly in the vessel’s course.

According to the observations of Mr. Knox, the Pied Wagtails which have wintered abroad reach the coast of Sussex about the middle of March, and on fine days may be seen approaching the shore, aided by a gentle breeze from the south, their well-known call-note being distinctly audible from the sea long before the birds come in sight.

The neighbouring fields, where but a short time previously not a bird of the kind was to be seen, are soon tenanted by numbers, and for several days they continue dropping on the beach in small parties. The old males come first, while the females and males of the previous year do not appear until some days later. After resting near the coast for a few days the new comers proceed inland, and any good observer there stationed may perceive how much the numbers of the species increase at this season. About the middle of August there is a general return movement towards the coast, and the Wagtails now first become gregarious. At that time Mr. Knox has frequently observed them in the interior of the county, where they remain but a few days, making way for fresh detachments, which in their turn follow the same route to the sea. At the end of the month, or early in September, they may be seen of a morning, flying invariably from west to east, parallel to the shore, but following each other in constant succession.

These flights continue from daybreak until about ten o’clock in the forenoon, and so steadily do the birds pursue their course that even when one or more of an advancing party have been shot, the remainder do not fly in a different direction, but opening to right and left close their ranks and continue their progress as before. During this transit their proximity to the coast depends to some degree on the character of the country lying between the South Downs and the sea; but as they advance towards Brighton, the migrating bands, consisting chiefly of the young of the year, accumulate in vast flocks, and thus they seek the adjoining county of Kent, whence the voyage to the continent may be performed with ease and security even by birds but a few months old, and unequal to protracted flights.[36]

The habits of the Pied Wagtail are so generally known, that little need be said here upon the subject. Its partiality for shallow water, where it preys upon aquatic insects, and even small fish, such as minnows and sticklebacks, has led to its being familiarly known as the Water Wagtail, although it is not more aquatic in its habits than other members of the genus, indeed, scarcely so much as one species, the Grey Wagtail, whose haunts seem inseparable from the water-side.