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)
Although somewhat local in its breeding haunts, this species is fairly abundant round all our coasts in winter. It is a Sea-Duck, being seldom found far inland, and its food consists of small mollusca and marine insects, which it seeks on our flat estuaries and along the shore.
A rabbit-burrow in sand-dunes near the sea is chosen for a nesting-site, and lined with a little grass, to which is subsequently added an abundance of grey down from the body of the female. Occasionally it makes its own burrow, or other sites such as crevices between boulders or under furze bushes are selected. The eggs, generally ten in number, are creamy white. As soon as they are hatched the mother leads her brood to the shore, where they feed, making for the sea on the first sign of danger.
During the pairing season this bird is very noisy, the male uttering a short whistle, while both sexes run round each other with out-stretched neck, making a curious guttural chuckle.
In winter large flocks of these birds visit us from the Continent. These flocks may be seen resting out at sea by day and come in to feed on the soft ooze by night; they are of course more partial to flat and sandy parts of the coast, but may nevertheless often be found in small sandy bays on an otherwise rocky shore.
The head and neck are glossy bluish black; the scapulars and primaries black. There is a broad band of bright chestnut across the back and breast, and a black stripe along the centre of the under parts. Speculum green. The rest of the plumage is pure white. Legs flesh pink; bill crimson. The sexes are alike, but the female is smaller and duller. The male has a crimson knob at the base of his bill which swells up considerably during the breeding season.
The young bird lacks the chestnut band, the head and neck are dull brownish black, the scapulars greyish brown, and in its first autumn it assumes a plumage similar to the adult female, but duller. Length 25 in.; wing 13 in. Both sexes assume in July a much duller plumage, somewhat resembling that of the young in their first winter.
THE RUDDY SHELD-DUCK
Tadorna casarca (Linnæus)
The Ruddy Sheld-Duck is a South-eastern European species, breeding on the shores of the Levant and throughout Northern Africa, but it is rare on the north shores of the Mediterranean west of the Adriatic. It has several times been noted as a straggler to England, and in 1892 many flocks appeared in different parts of the country.