(RED-BREASTED MARSH-BIRD.)
+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.