(2246) Cygnus olor.
The Mute Swan,
Anas olor Gmelin, Syst. Nat., i, p. 502 (1788) (Russia). Cygnus olor. Blanf. & Oates, iv, p. 413.
Vernacular names- None recorded.
Description. The whole plumage white with the exception of the lores, which are black.
Colours of soft parts. Iris dark brown; upper mandible reddish-horny, the tubercle, base, nostrils, margins and nail black ; lower mandible wholly black; legs and feet dull black.
Measurements. “Wing 560 to 622 mm.; tail 189 to 198 mm.; bill from knob 70 to 85 mm.; 5: wing 535 to 570 mm.; bill from feathers 72 to 90 mm" (Witherby).
Weight about 15 to 20 lbs., in a wild state rarely running up to 24 to 25 lbs. In a domesticated state birds of over 30 lbs. occur.
Young. Crown brown with white tips to the feathers ; sides of head and neck mixed grey and white; upper parts pale grey-brown, the centre of the mantle paler and more grey; some of the scapulars white at the base; underparts white suffused with grey-brown on the flanks, sides of the breast and under tail-coverts.
Nestling in down. Upper parts greyish-brown; underparts white.
Of the specimens in India nearly all have been young birds retaining traces of the juvenile plumage, the tubercle absent or only slightly developed and the feathers of the forehead and the base of the bill prolonged to a point.
Distribution. Central and South-Eastern Europe, Western and Central Asia. In Winter it migrates South to Africa on the North-East, Palestine, Arabia, Asia Minor, Afghanistan, Baluchistan and North-West India. The occurrences in India are as follows: - One, Shah Alum River, Punjab, 1857 (W. Mahomed Amar); two, Jubee Stream, N. W, Provinces, 1871 (Unwin); three, Sewan, Sind, 1878 (Watson); two, do., do., 1878 (Waterfield & Sinclair); two, 1900 (Jones); one, Karachi, Sind, 1900 (Cumming); Sita Road Station, 1900 (Natives); four, Baluchistan [Frontier, 1900 (Matthews); Manchur Lake, Sind, 1900 (Crerar); one, Metong, Indus (Wragge); Naoshera, Punjab, 1910 (O'Brien); one, River Sohan, Johore, 1911 (Lord); one, Lahore, 1911 (Glascock).
Nidification. In its wild state this Swan is said to breed either in colonies or singly, making the usual large nest of all kinds of vegetable rubbish and water-weeds, more or less lined with down. The nests may be built in swamps in vast reed-beds, on open tundra round lakes and ponds or upon small islands in rivers and lakes. The eggs are said normally to number six or seven but clutches of eight to twelve have been recorded, whilst others of three and four have been found incubated. They differ from other Swans' eggs in being greenish in colour. Jourdain gives the following measurements : - Average of fifty 114.5 x 73.1 mm.: maxima 122.9 X 77.1 and 119.0 x 80.0 mm.; minima 105.0 x 73.0 and 112.0 x 70.0mm.
The breeding-season is April and May.
Habits. Much the same as those of other Swans. Its diet is said to be mainly vegetarian, mixed with worms, snails and insects.