Page:The Emu volume 3.djvu/123

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Vol. III. 1903 ]
Milligan, Description of a New Gymnorhina.
101

surface dingy brownish-black, with greyish-white edgings; bill changing from horn colour to bluish, but without glaze or polish. Over-all measurements, 12½ × 4¼; tail-band, 2⅛; culmen, 2.25 inches. In another, but slightly older bird, of the same sex, the dark-coloured plumage showed a sheen, except on the lower abdomen, which was brown. The vent feathers were long and brownish, with white ends; wing edges mottled. Over-all measurements, 13 × 4¼; tail band, 2; culmen, 2.25 inches. In a third young female the mantle feathers were deep black, with sparse and indistinct white edgings, producing a spotted appearance, and the feathers of the rump were black with white edgings, producing a barred appearance. Over-all measurements, 12 × 3⅝; tail-band, 2¾; culmen, 2 inches. In a fourth young bird of the same sex the head was brownish-black, with white edgings, irregularly disposed; under surface dingy blackish brown. Over-all measurements, 12⅜ × 4; tail-band, 2½; culmen, 1⅞ inches.

The measurements of the tails of all birds varied from 5.75 to 6.6 inches. It is perhaps worthy of remark that in many instances the tails of the young birds exceeded in length those of fully matured ones.

As the dates of capture have only in one or two instances been inscribed on the labels attached to the skins, I regret to say that I have been unable to trace the several colour changes (for such I am convinced occur) of the first year, and the subsequent feather changes, and, perhaps, colour changes. Whilst on the subject of feather-change I must mention an instance of an unseasonal moult in an adult male shot in the vicinity of Perth in the month of January. The feathers of the head and neck had (probably the result of some misadventure) been lost, and those portions showed new feathers encased in sheaths appearing on the otherwise nude surfaces. The ordinary moult would take place in June or July.

From the foregoing observations, and from the result of examination not here recorded, and from field notes and observations of birds, in captivity, I deduce the following as characteristic of an adult male and female in full and mature plumage: —

Male.—(1) Colour dispositions sheeny blue-black and snow-white, sharply contrasting and uniform; (2) wing edges pure white, not mottled; (3) stems of feathers of white and black portions of tail correspondingly and relatively white and black; (4) terminal black tail-band not exceeding 1 inch; (5) vent-patch pure white, small, and inconspicuous; (6) mandibles polished pale blue for basal half, deep blue distal half.

Female.—(1) Similar to male, except mantle, which is black, with conspicuous and well-defined white edgings to feathers; (2) similar to male; (3) stems of feathers wholly black; (4) terminal black band exceeds 1 inch; (5) and (6) similar to male.

In well-advanced females of the first year the white band and almost black band are the distinguishing characteristics.