(2247) Sarkidiornis melanotus.
The Nukhta or Comb-Duck.
Anser melanotus Pennant, Indian Zool., p. 12, pi. 12 (1769) (Ceylon). Sarcidiornis melanonotus. Blanf. & Oates, iv, p. 423.
Vernacular names- Nukhta (Hind.); Mukwa (Chota Nagpur); Naki-hansa (Ooriya); Jutu-chiluwa (Tel.) - Dod-sal-haki (Can.); Neer-koli (Coimbatore) ; Tau-bai, Mauk-ton (Burma) ; Bowk-bang (Karen); Karo Rang (Sind).
Description. - Male. Head and neck white, spotted with metallic-black feathers, coalescing more or less on the crown, nape and hind-neck; lower neck and whole lower plumage white, tinged sometimes with rufous-grey; rest of upperplumage and wings black, glossed with green and blue, except on the secondaries, which are glossed with brown, and the scapulars, on which the gloss is purple; tail dark brown; sides of the body tinged with grey; a black mark, almost a demi-collar, on each side of the neck ; a black band in front of the under tail-coverts descending from the rump ; lower back grey.
Colours of soft parts. Iris dark brown ; bill and comb black ; legs and feet plumbeous. Young birds are said to have the iris almost black.
Measurements. Wing 339 to 406 mm.; tail 139 to 153 mm.; tarsus about 64 to 75 mm.; culmen about 63 to 70 mm.; comb 55 to 60 mm. in breeding-season.
Female only differs in having no comb and in being rather smaller; the black everywhere is much less glossy and the lower back and rump are grey-brown; the neck and head are often more profusely marked with black. Wing about 280 to 309 mm.; culmen about 59 to 66 mm.
Nestling in down. Upper parts dull grey-brown; a white frontal line is continued back over the eye; a white crescentic band outlines the back of the rather darker crown; narrow brown bands commence behind the ear-coverts and meet on the hind-neck ; two white patches on the side of the back near the base of the wing and two others on the sides of the rump; lower surface greyish-white.
Distribution. Bare in the Punjab in the cis-Sutlej; absent from North and West Sind, resident over the whole of the rest of India and Ceylon where there is water available. In Eastern Bengal it is rare but has occurred in the Sunderbunds, Jessore and Khulna; in Assam it has occurred in Cachar, Sylhet and the Looshai Hills. In Burma it is rare in the North but becomes common in Pegu.
Nidification. The Comb-Duck breeds throughout its area from June to September. Normally the nesting-site is a large natural hollow in some tree, the eggs being laid either on the bare wood or upon a rough nest of sticks, grass and leaves but no down appears ever to be used as a lining. Sometimes the bird selects a hollow where the main branches spring from the trunk; occasionally a hole in a bank is used and, still more rarely, the nest of a Vulture or Stork. As a rule the full clutch numbers eight to a dozen but Anderson once found forty eggs in a nest, whilst Livesey took no fewer than forty-seven from one nesting hole. In colour the eggs are a pearly-white, very highly glossed when fresh and one hundred average 61.8 X 43.3 mm.: maxima 66.7 x 44.1 and 63.2 x 45.4 mm.; minima 56.0 x 42.5 and 58.0 x 42.0 mm.
Habits. The Comb-Duck is a bird of well-wooded open country, frequenting neither dense forest nor open plains. Ample water is, of course, a necessity but this may be marsh, lake, river or canals; in such places in is found in small flocks, probably families which break up when the breeding-season commences. These Ducks fly well and strongly, swim equally well and fast and are said by Tickell to be expert divers. They also run and walk well and can perch on any branch large enough to hold them without being grasped. Their ordinary note is a low, hoarse croak but in the breeding-season they have a fine loud " houk." They feed principally on a vegetarian diet, of which rice, both in grain and young leaves, forms an unfortunately large part. They also eat worms, spawn, small frogs-, larvae and occasionally small fish. Young ducklings when they first fly are good-eating but old birds are not worth shooting for "the pot.