This species, which is smaller than the Whooper, visits us regularly every winter, and is in some places the commoner of the wild Swans. In Scotland it is abundant in some seasons as it is also in Ireland, but on the coasts of England and Wales it is always rather scarce. It breeds in the Far North to the east of the White Sea. It may be distinguished from the Whooper by its smaller size and the extent of the yellow on the beak, which does not quite reach the nostrils. Length about 46 in.; wing about 21 in. THE MUTE SWAN Cygnus olor (J. F. Gmelin) In this country the Mute Swan is only met with in a state of semi-domestication, having been introduced at some early period of history. It is now, however, widely distributed throughout our islands. Inhabiting lakes, rivers, and ornamental waters, it feeds on aquatic weeds and grain, and is extremely useful in preventing an undue growth of weeds in ornamental ponds and lakes. The nest is a huge structure of straw and rushes, built upon the edge of the water, or in the centre of a reed-bed. The eggs, which vary in number from five to nine or ten, are of a uniform pale green, and are hatched after some five weeks’ incubation. The young, which are covered at first with greyish down, are carefully tended by both parents, and when tired nestle on their parents’ back. In olden times the right to keep Swans on the Thames was granted by the King to many of the City Companies, and in the autumn of each year (a custom which is still continued) the young Swans are caught up and marked on the bill with the private mark of the Company to whom they belong. This is known as “Swan upping.” The male is known as the “Cob” and the female as the “Pen,” and the rules and regulations clearly state how the brood shall be awarded in the event of the Cob and Pen belonging to different Companies, while the landowner on whose ground they nest also comes in for a share. At the nest the male Swan is very savage, attacking any intruder with his bill and with savage beats of his powerful wings; his mate, however, is very quiet and will allow herself to be pushed off the nest with no stronger protestation than a subdued “hiss.” This Swan is not mute as its name implies, but has a loud trumpet-like note, to which, however, it seldom gives utterance. In a purely wild state, this species may be found breeding in Denmark and the south of Sweden, and it is a common breeding species in South-eastern Europe. From its northern breeding haunts it migrates in winter, many probably coming over to our shores. The plumage is pure white; the bill reddish orange with a black knob at its base. This knob is much larger than in the male. The young are greyish drab. The so-called “Polish Swan” is a variety of this species, in which the young are white. Length about 56 in.; wing 27 in. THE COMMON SHELD-DUCK Tadorna cornata (S. G. Gmelin)