95. THE COMMON SHELD-DUCK.
Tadorna tadorna (LINNAEUS).*
Primaries uniformly black.
Axillaries and under wing-coverts white. Speculum metallic green, or bronze, with the outer web of the adjoining secondaries chestnut. Tail white, tipped with black or brown.
MALE : Breast and mantle rich chestnut. FEMALE : Breast and mantle dull chestnut, undulated with black.
VERNACULAR NAMES -.—Rararia, Shah-chakwa, Sufaid-surkhab, Hind.; Niraji, Sind.
THE Common Sheld-Duck or Burrow-Duck is a winter visitor to the northern parts of the Empire, but is nowhere common. It has been met with in the Punjab, Sind, Kathiawar, Cutch, the North-west Provinces, Oudh and Bengal. It is said to be rare in Oudh, and it has been observed in the Calcutta market in March and April only. Mr. Eden shot this Duck near the Mirzapur Tea Estate in Sylhet. Mr. Forsyth recorded it from the Bhramaputra river, near Dhubri. Mr. H. Fasson obtained it in Ghittagong. Captain A. W. Newbold sent me a specimen which he shot at Myitkyina, on the upper portion of the Irrawaddy river, in December. It also appears to have occurred at Meiktila, which is perhaps as far south as this species is ever likely to reach in Burma.
The Common Sheld-Duck is a permanent resident in many portions of its extensive range; migratory, but to no great extent, in others. This species ranges from Western Europe eastwards to Japan and China. It is seldom found north of the 6oth degree of latitude, but it has been observed farther north in Europe than in Asia, which is due perhaps to there being more frequent observers in the former continent than in the latter. In winter there seems to be a partial movement of these Ducks, and they are then observed on the southern shores of the Mediterranean, South-western Asia, India, and Southern China. In India these Ducks arrive about the middle of November, and some remain till the middle of April.
The Common Sheld-Duck is usually a sea-coast bird, but in India, where suitable sea-coast is restricted, it is found chiefly on the larger lakes and rivers. It is altogether so uncommon in many parts of its Indian range that its habits have not been closely studied by Indian naturalists, and therefore with respect to their habits I shall quote extensively from English authors who have had better opportunities. But first I shall record a few remarks by Mr. Hume. He says:—"Like the Brahminy Ducks, they are essentially shore birds ; until disturbed, I never saw one swimming about in the open water. They are either prowling about on the land near to the water's edge, or else paddling in the shallows close to this latter. With us they are always seen in pairs, or in small parties of three to five in number— never in considerable-sized flocks. They walk with more ease than the Mallard, more like the Barred-headed Goose, but less pompously and with quicker steps. They rise and fly more like other Ducks, with less noise and more rapid beats of the wing than either the Bar-head or Brahminy."
Seebohm, whose accounts of the habits of birds are always so complete, remarks:— " The breeding-grounds of the Sheldrake are for the most part mild enough in temperature for it to be a resident, but in the northern portion of its range it is a migratory bird arriving in March and leaving in October. It is almost exclusively a marine species, breeding in Europe on sandy coasts; but in Asia east of the Caspian, in Turkestan and Mongolia, it frequents inland salt lakes, and in Eastern Siberia it is confined to the salt steppes. In its winter quarters in India, though it sometimes visits the broads and large sheets of fresh water, it always seems to prefer the coast. In England ft is rarely if ever seen inland, always preferring the sandy coasts, especially where the sand is blown into hills, locally called ' links' or ' dunes.' Nowhere is the Sheldrake more abundant than on the west coast of Denmark, where it may almost be said to live in a state of semi-domestication, the peasants making artificial burrows in the sand-hills and robbing the nests systematically until the middle of June, when they allow the birds to begin to sit. Under these circumstances it may almost be said to breed in colonies, but in a truly wild state it is never known to do so.
" The Sheldrake is a somewhat shy bird, and is more or less gregarious even in the midst of the breeding season. I found it extremely abundant on the shores of the Black Sea, and small parties of them, most consisting of last year's birds which were probably not breeding, were the most conspicuous objects on the lagoons which are so numerous between the Danube and the coast. The call-note of the Sheldrake, which is common to both sexes, is a harsh quack. During the pairing season the male utters a clear, rapidly repeated whistle or trill; and when the young are hatched, his anxious alarm-note to his mate on the approach of danger may constantly be heard, and resembles the syllables kor, kor, uttered in a deep tone. The flight of the Sheldrake is performed by slow and laboured beats of the wings, very unlike the rapid motion of smaller Ducks, and much more resem¬bling that of the Swan. Although the Sheldrake seldom or never dives, it obtains most of its food in shallow water, aquatic plants, mollusks, and various water-insects being obtained in the fresh-water lagoons, whilst seaweeds and marine animals of various kinds are sought for on the shore. In searching for food they continually immerse the head and upper half of the body, only the tail and rump being visible. On the land they walk with ease, like a Goose. The Sheldrake resembles the Geese in some of its habits, and frequents the pastures, especially in early morning, but not so much to feed upon grass as to search for worms and slugs.
"So far as is known the Sheldrake never breeds in the open, but always in a burrow, generally in that of a rabbit, but less frequently in that of a fox or a badger ; and there are reliable instances on record of their having hatched out their young whilst the original owner of the burrow was still in occupation. Sometimes the birds excavate a burrow for themselves, which is generally more or less winding, and extends from six to twelve feet, ending in a chamber, in which the eggs are laid upon a handful of dead grass and scraps of moss. Where it is protected, the Sheldrake is an early breeder, eggs being frequently laid before the end of April; but in localities where it is disturbed, fresh ones may be found as late as the end of May or the beginning of June. Seven to twelve is the ordinary number, but occasionally as many as sixteen are laid; and where the nests are regularly robbed, as many as thirty have been obtained from a single burrow in one season."
Mr. Stevenson in his " Birds of Norfolk " thus summarises the habits of this Duck: " Mr. Selby, from his own observations of the habits of this species upon the Northumbrian coast, states that the males do not pair until their plumage is perfected in the second year, but, once paired, remain constant to the same mate. In the male, also, at the commencement of the breeding season, the fleshy knob at the base of the upper mandible, scarcely perceptible in autumn and winter, ' begins to swell and acquires a beautiful crimson hue, and when at its full development, is nearly as large as a marble.' The nests are formed of ' bent grass and other dry vegetable materials,' lined with soft down from the old birds' breasts ; and the eggs, from twelve to sixteen in number, ' of a pure white or slightly tinged with green,' are incubated in thirty days, and are sometimes ten or twelve feet from the entrance to the burrow. The male sits on the eggs when the female is off feeding, and both birds, like the partridge and wild duck, will feign lameness and adopt other stratagems to decoy intruders from the vicinity of their young when able to quit their nesting holes, hence probably the name of ' sly goose' applied to this species in some localities. The young are sometimes carried in the bills of their parents down to the sea. St. John, in his ' Natural History and Sport in Moray ' (p. 293), refers to the strange instinct which enables the female, sitting on her eggs many feet under ground, and more or less distant from the sea, to know to a moment when the tide begins to ebb, and then and then only to betake herself to the freshly exposed feeding grounds. The males of this species vary much in size, as may also the females, but the latter are always smaller than the males as well as less brilliant in colour; but, unlike the true Ducks, both sexes in the genus Tadorna are alike in plumage, and retain it when once fully acquired. The flesh of the Sheldrake is coarse and unpalatable, and its food consists, according to Selby, of ' marine vegetables, molluscous shell-fish, insects, etc.;' but so minute are some of the forms of mollusca which afford them a meal, and so great their consumption, that Thompson, in his ' Birds of Ireland' (vol. iii. p. 69), describes the crop and stomach of one of these birds as containing by a careful computation not less than twenty thousand minute mollusca."
The Common Sheld-Duck lays from April to the beginning of June. The eggs number from seven to twelve, and occasionally as many as sixteen. They are smooth and have little gloss. In colour they are creamy white or very pale yellowish white. They measure from 2.5 to 2.75 in length and from 1.9 to 2 in breadth. The down, taken from the nest, is of a beautiful lavender-grey colour.
The adult male has the whole head and neck glossy black. The upper part, of the mantle and breast is white, forming a broad collar. The lower part of the mantle and breast is rich chestnut, forming a broad band below the white collar. A black band occupies the middle of the chestnut breast, and widens into a broad patch which covers the central portion of the abdomen. The under tail-coverts are pale chestnut. The remainder of the lower plumage, the axillaries and the under wing-coverts, are white. The whole of the upper wing-coverts, the inner scapulars, the back, the rump, and the upper tail-coverts are white, frequently tinged with pale buff. The outer scapulars are deep black. The tail is white, tipped with black. The primaries and their coverts are black. The outer secondaries are metallic green or coppery bronze on the outer, largely white on the inner, web. A few of the secondaries next the inner side of the speculum, are chestnut on the outer web, with an inner black margin, and white on the inner web. The inner secondaries are entirely white. Immediately after the moult, the chestnut feathers of the plumage are all margined paler. These margins get worn away after some time. The adult female resembles the adult male, but has the chestnut parts of the body-plumage of a dull tint, each feather mottled or undulated with black, and narrowly edged with white. The dark portion of the lower plumage is brown instead of black; and the inner secondaries are ashy.
The duckling, on moulting into first plumage, about November, has the head and upper neck dark brown, with the cheeks, and a space all round the bill, white. The remaining body-plumage is pure white, except a broad band covering the lower portion of the mantle and the sides of the breast, which is pale chestnut, the feathers undulated with black, and narrowly tipped with white. The white tail is tipped with brown. The inner scapulars are white, and the outer brown, narrowly margined with white. The upper wing-coverts are white, but the lower series is tinged with ashy. All the quills of the wing, except the first four primaries, are tipped with white, and the first two primaries are largely white at the base. The speculum is much duller than in the adult. The secondaries next the inner side of the speculum are dull chestnut on the outer webs, and the remaining inner secondaries are dark ashy. The knob on the bill of the male does not make its appearance till the breeding season of the second year.
The young bird attains the complete plumage of the adult female in the course of the first winter.
Male: length about 24; wing 13; tail 4 1/2. Female : length about 21; wing 11 1/2; tail 4. In the adults the bill is red, the nail dusky; the irides brown; the legs and feet flesh-coloured. Weight up to nearly 3 lb., as recorded by Messrs. Hume and Marshall, but probably heavier birds are to be met with.
* Tadorna cornuta of the British Museum Catalogue.