Mergus serrator, Lin.
972bis. :- Murray's Vertebrate Zoology of Sind, p. 308 ; Game Birds of India, Vol. III, p. 305.
THE RED-BREASTED MERGANSER.
Length, 24 to 26; expanse, 29 to 32.5; wing, 9 to 10; tail, 3.1 to 4.2 ; tarsus, 1.8 to 2.05; bill at front, 2.4 to 2.5.
In the male the bill varies from orange-red to deep vermilion, is more or less dusky on the edge, and has the nail varying from pale yellowish-grey to almost black. In young females there is more dusky on the upper mandible, where the red is often only a lateral band.
The whole head, chin, throat and the neck all round, for about one inch, black, glossed with metallic green on the sides of the head and a bluer sheen elsewhere; along the middle of the crown and occiput runs a comparatively narrow line of excessively narrow, more or less disintegrated, webbed, elongate feathers, of which the longest are over three inches in Length, forming a conspicuous crest; the rest of the neck all round, to just the base, pure white, with a conspicuous narrow black line down the centre of its hinder aspect; at the base of the neck a light brownish-rufous, or pale brownish-chesnut band, extends all round, narrower behind and broadening into a crop-patch. This band is streaked longitudinally with blackish-brown. The interscapular region and upper back, the extreme sides of the breast and scapulars, velvet-black; outside the scapulars and between these and the wing there is a conspicuous patch of long white feathers; the primaries and their coverts (which latter are darkest), the shoulder of the wing and lesser-coverts just above the carpus, blackish-brown ; the rest of the lesser and median-coverts pure white ; the secondary greater-coverts black, all, except the first three, very broadly tipped with white, but leaving a portion of their black bases visible below the white median-coverts, thus forming the first black bar across the white of the wing; the secondaries are black, all, except the first three, very broadly tipped with white ; tertiaries white, conspicuously margined with black, except the last three, which are black ; axillaries pure white ; rest of the lower parts white, with, in life, a beautiful salmon or buffy tinge which disappears in the skin ; flanks white, vermiculated with greyish-black ; middle and lower back, rump and upper tail-coverts, white, with very delicate and close vermiculations of dull black, producing a grey effect; tail dull brown; lower wing-coverts white.
The female has the entire crown, occiput and crest brown, with more or less of a dull rufous or chesnut tinge, and rather ashy towards the forehead ; sides of the head and neck all round pale dull brownish chesnut; chin white ; throat albescent; breast and entire lower parts white or pinkish-white in life, only at the base of the throat and crop the grey-brown bases of the feathers show through to a certain extent like hidden bars; interscapulary region, mantle, lower back, rump and upper tail-coverts brown ; most of the feathers with paler margins ; quills dusky-black; secondaries and their greater-coverts black, all but the first three broadly tipped with white; tertiaries blackish-dusky, paling anteriorly, whitish towards the tip ; the innermost mostly white, with a black outer margin ; tail like the back.
Both sexes from the above description resemble the Goosander, but may be distinguished by their small size, and in proportion to their length much thinner bills. :- Hume's Stray Feathers, Vol. IX, p. 268.
The Red-breasted Merganser is a very rare cold weather visitant to the Mekran and Kurrachee Coast.