Leistes superciliaris, Hudson, P. Z. S. 1870, p. 333 (Buenos Ayres); Scl. et Salv. Nomencl. p. 38; Durnford, Ibis, 1877, p. 175 (Buenos Ayres); White, P. Z. S. 1882, p. 602 (Salta); Barrows, Bull. Nutt. Orn. Cl. viii. p. 136 (Entrerios); Scl. Cat. B. xi. p. 349. Trupialis guianensis, Burm. La-Plata Reise, ii. p. 490 (Banda Oriental).
Description.—Brownish black; superciliaries pale brown; bend of the wing and body beneath from the chin to the middle of the belly bright scarlet; bill and legs black; length 7·0 inches, wing 4·0, tail 2·5. Female pale brown, above variegated with black, below stained with red on the breast; flanks and lower belly striated with black; tail cinereous brown, with black cross bars.
Hab. Argentina, Paraguay, and E. Brazil.
The most interesting point concerning this species is the very great difference in habits, as well as appearance, existing between the sexes. In form it resembles the Starling of Europe, but is a trifle smaller and has a shorter tail. The male is black, the upper parts faintly mottled with yellowish grey; there is a straw-coloured stripe over the eye; the throat and breast bright crimson. The female is a smaller bird, and in colour dull fulvous grey, mottled with fuscous; the red tint on the breast scarcely perceptible.
These birds are migratory, and appear everywhere in the eastern part of the Argentine country early in October, arriving singly, after which each male takes up a position in a field or open space abounding with coarse grass and herbage, where he spends most of the time perched on the summit of a tall stalk or weed, his glowing crimson bosom showing at a distance like some splendid flower above the herbage. At intervals of two or three minutes he soars vertically up to a height of twenty or twenty-five yards to utter his song, composed of a single long, powerful, and rather musical note, ending with an attempt at a flourish, during which the bird flutters and turns about in the air; then, as if discouraged at his failure, he drops down, emitting harsh guttural chirps, to resume his stand. Meanwhile, the female is invisible, keeping closely concealed under the long grass. But at length, attracted perhaps by the bright bosom and aerial music of the male, she occasionally exhibits herself for a few moments, starting up with a wild, zigzag flight, like a Snipe flushed from its marsh, and, darting this way and that, presently drops into the grass once more. The moment she appears above the grass the male gives chase, and they vanish from sight together. Thus, while in colour, habits, language, and even in its manner of soaring up like a rocket to let off its curious melody, the male is the most conspicuous of small birds, the female, acted on in an opposite direction by natural selection, has been, so to speak, effaced. While flying, they do not look like birds of the same species: the male moves with wings rapidly fluttered, like a Starling, but with a slower, more laborious flight, and without deviating; the female, in her eccentric movements in the air, reminds one of a large moth driven from its hiding-place, and flying about confused with the glare of noon.
The nest is made of dry grass on the ground, so cunningly concealed that it is most difficult to find. The eggs are four, white, spotted with reddish brown. When they have young, I have never been able to detect the female flying about in search of food.
All through the summer these birds are solitary, but when migrating in the autumn, though many are seen travelling singly, and appear very conspicuous as they fly laboriously in a straight line, at an altitude of about twenty yards from the surface, others are seen making their journey in small flocks or parties composed of six to a dozen individuals. These are the males. The females travel separately, in twos or threes or singly, flying nearer to the earth, with frequent pauses, when the wings cease beating, and intervals of gliding, also darting occasionally to one side, as if the bird had suddenly taken fright.
[101.] AMBLYRHAMPHUS HOLOSERICEUS (Scop.).
(SCARLET-HEADED MARSH-BIRD.)
Amblyrhamphus holosericeus, Hudson, P. Z. S. 1870, p. 114 (Buenos Ayres); Scl. et Salv. Nomencl. p. 37; Durnford, Ibis, 1877, p. 174 (Buenos Ayres); Gibson, Ibis, 1880, p. 18 (Buenos Ayres); White, P. Z. S. 1882, p. 602 (Buenos Ayres); Barrows, Bull. Nutt. Orn. Cl. viii. p. 135 (Entrerios); Scl. Cat. B. xi. p. 351. Amblyrhamphus ruber, Burm. La-Plata Reise, ii. p. 491 (Entrerios, Santa Fé, Paraná).