THE WATER FOWL.
THE Water-Fowl comprise the Swans, the Geese, and the Ducks.
The Swans are perhaps best separated by reason of their long necks and bare cheeks, but there is no line of demarcation between the Geese and the Ducks. The typical Goose and the typical Duck of our farmyards are sufficiently distinct, it is true; but when treating of a large number of species of Water Fowl, we find a perfect chain of links between the Geese and Ducks, just as in treating of the Gallinaceous Birds we found the Pheasant and the Partridge linked together by numerous groups possessing some of the characters of both species.
I have, therefore, not attempted to divide the Water Fowl into three large sections—Swans, Geese, and Ducks—but have preferred to form these birds into small natural groups, to which I have assigned names which are partly sanc tioned by usage and partly suggested by considerations of structure, habits, and plumage.
The Water Fowl do not vary in form to such an extent as the Gallinaceous Birds, and it is consequently much more difficult in the case of the former to discover characters by which they may be grouped together or separated from each other. The primary character of importance among the Water Fowl is un¬doubtedly the pattern of colour presented by the primaries.
All adult Swans have the primaries pure white. I am aware that the South American Coscoroba Candida, is by many authors looked upon as a Swan, and that it has the primaries white tipped with black; but I believe that this bird is not a Swan, but a Goose. The neck is very short, the cheeks are feathered, and it bears little resemblance to a Swan in form or external structure.
The True Geese have a pattern of the primaries all their own. The outer primaries are grey tipped with blackish; the inner are uniformly black or blackish.
All the resident Ducks, and those Ducks the migrations of which are very limited or partial, have the primaries uniform, without a pattern: black or dark brown in the case of the Sheld-Ducks, the Comb-Ducks, the Whistling Ducks, the Wood-Ducks and the Grey Ducks; and grey or brown in the case of the Marbled and Stiff-tailed Ducks.
All the highly-migratory and rapid-flying Ducks have the primaries with the outer web of a very dark colour, and the inner web of a drab colour with a dark tip. The Ducks which have the primaries of this peculiar pattern are the True Ducks, the Golden-eyes, and the Mergansers.
Another pattern is presented by the Pink-headed Ducks and the Pochards. These have the outer primaries similar to those of the True Ducks, above described ; but the inner primaries are of the same white or pale colour as the speculum, but tipped with dusky.
The Scaup Ducks have the primaries very similar to those of the Pink-headed Ducks and Pochards, but the inner primaries, instead of being white or of a pale colour on both webs, have only the outer web white or of a pale colour, the inner web being dark.
The Cotton-Teal is one of the very few Ducks, in fact the only Indian one, in which the pattern of the primaries varies in the two sexes. It is in other ways a very anomalous Duck, one remarkable feature of its economy being that it has both a spring and an autumn moult.
It will be seen how important this pattern of the primaries is in determining Water Fowl. I have not restricted my examination of the colour-pattern of the primaries to the Indian Ducks alone. I have examined a large number of species of Ducks from all parts of the world, and it seems to me a character of the first importance for the classification and grouping of the Water Fowl.
The colour of the axillaries and of the speculum are also characters of much use in discriminating the Ducks. The shape and size of the bill, the shape of the tail and the number of feathers of which it is composed, the extent to which the hindtoe is lobed, and the size of the feet, are characters liable to great variation, and little reliance can be placed on them. They are generally of little use, and I have seldom referred to them.
The resident Ducks, and a few others which have nearly abandoned the migratory instinct, such as the Sheld-Ducks, have the usual autumn change and no other. The Cotton-Teal, but probably only the male of this, has two moults a year, as before remarked. The True Ducks, the Diving Ducks, the Golden-eyes and the Mergansers differ from all the above mentioned in respect to the way the moult is accomplished. The females have only the one autumn moult, but the males pass through a lengthened operation lasting probably four months. As soon as the female has commenced incubation, the drakes retire and flock together in the quietest spots they can find. They there commence a moult of the feathers of the head, neck, and body, and emerge from this operation in a plumage which very closely resembles that of the female. As soon as this has been accomplished, the drakes moult their quills. They then cast the plumage of the head, neck, and body again, and resume their ordinary brilliant male plumage. Drakes in the plumage of the female, or in post-nuptial plumage as I have termed it in the following pages, are very seldom seen or shot, and consequently specimens are very rare in museums. There is much doubt, even at the present time, regarding the post-nuptial plumage of the drakes of some of the commoner European species.
Young Ducks change from the downy stage into the plumage of the adult female. The males, almost immediately after this, commence to assume the plumage of the drake, and resemble him closely by the end of the first winter; but they do not acquire the mature, brilliant plumage of the perfectly adult drake till about the end of the third year.
I now append a synopsis of the sixteen groups of Water Fowl found in India. As in the case of the other Game birds, the characters given apply to both sexes, and also to the young bird, after the change from down to feather.
SYNOPSIS OF THE GROUPS OF WATER FOWL TREATED OF IN THIS WORK.
SWANS.— Primaries white in adults, pale brown in young birds; the neck as long as, or longer than, the body; the skin in front of the eye bare of feathers, except in very young birds ; the inner secondaries reaching to the tip of the longest primary ; the tarsus much shorter than the middle toe. Of wide distribution. P. 24.
TRUE GEESE.— Varying in size up to that of a domestic Goose; the outer primaries grey tipped with blackish, the inner primaries and the outer secondaries uniformly blackish ; all with white shafts ; the upper tail-coverts white ; the axillaries bluish grey or ashy. Of wide distribution. P. 38.
SHELD-DUCKS.— About the size of a small Goose ; primaries uniformly black ; axillaries white; wing-coverts white; speculum green or bronze; the outer web of the secondaries next the inner side of the speculum, chestnut. Of wide distribution. P. 79.
COMB-DUCKS.— About the size of a small Goose ; primaries uniformly black ; axillaries black; head and neck white, spotted with black. Of wide distribution. P. 101.
WHISTLING DUCKS.— About the size of a small Duck; primaries, axillaries, and under wing-coverts uniformly black; feathers of the back broadly margined with rufous. Of wide distribution. P. 110.
COTTON-TEAL.— Much smaller than a Common Teal; primaries uniform brown, with or without a large white patch; axillaries black, or else brown margined with grey; nearly all the secondaries broadly tipped with white. Of wide distribution. P. 125.
WOOD-DUCKS.— About the size of a small Goose ; primaries uniformly black ; axillaries white ; upper wing-coverts white, with a broad black band separating them from the slaty-blue speculum. The eastern part of the Empire. P. 136.
GREY DUCKS.— Varying in size from that of a common Teal to that of a domestic Duck; primaries uniformly black, or with the inner web of a slightly paler black than the outer; axillaries white; under tail-coverts never plain white nor barred across; in the closed wing, the first secondary reaching to about the tip of the longest primary coverts. Confined to the Indian Empire. P. 147.
TRUE DUCKS.—Varying in size from that of a common Teal to that of a domestic Duck; the outer web of the primaries blackish, the inner web drab, with a blackish tip; axillaries white, or white mottled with brown; under tail-coverts never plain white nor barred across; in the closed wing, the first secondary falling short of the tip of the longest primary coverts by more than half an inch. Of wide distribution. P. 168.
MARBLED DUCKS.— Rather larger than a common Teal; primaries grey on both webs, with dusky tips, the first five or six with a silver-grey tinge on the outer web; axillaries white, barred with brown near the tips; upper plumage marked with large, roundish, pale buff spots; under tail-coverts barred across. Of wide distribution. P. 272.
PINK-HEADED DUCKS.— About the size of a domestic Duck; outer primaries with the outer web much darker than the inner; inner primaries with both webs of the same pale vinous drab as the speculum, and all tipped with dusky; axillaries brown, mottled with white; the whole lower plumage, together with the sides of the body, of one uniform dark colour. Confined to the Empire. P. 282.
POCHARDS.— Varying in size from that of a small Wigeon to that of a domestic Duck; outer primaries with the outer web much darker than the inner; inner primaries with both webs of the same white or grey colour as the speculum, and all tipped with dusky; axillaries white, or white mottled with brown at the tip; the lower plumage and the sides of the body never of one uniform colour throughout. Of wide distribution. P. 296.
SCAUP DUCKS.— About the size of a Wigeon ; outer primaries with the outer web much darker than the inner; inner primaries with the outer web white or much paler than the inner, and all tipped with dusky; axillaries white, or white mottled with brown at the tips. Of wide distribution. P. 334.
GOLDEN-EYES.— About the size of a Wigeon; the outer web of the primaries blackish, the inner web drab, with a blackish tip; axillaries uniformly blackish or brown; the middle secondaries entirely white. Of wide distribution. P. 357.
STIFF-TAILED DUCKS.— Rather larger than a common Teal; primaries uniform drab brown, with darker tips; axillaries white; under tail-coverts cross-barred ; base of the upper mandible much swollen; tail composed of narrow, stiff feathers, projecting fully three inches beyond the coverts. Of wide distribution. P. 373.
MERGANSERS.— Varying in size from that of a common Teal to that of a domestic Duck; the outer web of the primaries blackish, the inner web drab, with a blackish tip; axillaries white; under tail-coverts plain white; margins of the bill furnished with close-set sawlike teeth. Of wide distribution. P. 386.