Of the Argentine cow-bird (Molothrus bonariensis) Hudson says (Argentine Ornithology, vol. i, p. 73):  “The song of the male, particularly when making love, is accompanied with gestures and actions somewhat like those of the domestic pigeon.  He swells himself out, beating the ground with his wings, and uttering a series of deep internal notes, followed by others loud and clear; and occasionally, when uttering them, he suddenly takes wing and flies directly away from the female to a distance of fifty yards, and performs a wide circuit about her in the air, singing all the time.  The homely object of his passion always appears utterly indifferent to this curious and pretty performance; yet she must be even more impressionable than most female birds, since she continues scattering about her parasitical and often wasted eggs during four months in every year.”

Of a tyrant-bird (Pitangus Bolivianus) Hudson writes (Argentine Ornithology, vol. i, p. 148):  “Though the male and female are greatly attached, they do not go afield to hunt in company, but separate to meet again at intervals during the day.  One of a couple (say, the female) returns to the trees where they are accustomed to meet, and after a time, becoming impatient or anxious at the delay of her consort, utters a very long, clear call-note.  He is perhaps a quarter of a mile away, watching for a frog beside a pool, or beating over a thistle-bed, but he hears the note and presently responds with one of equal power.  Then, perhaps, for half an hour, at intervals of half a minute, the birds answer each other, though the powerful call of the one must interfere with his hunting.  At length he returns; then the two birds, perched close together, with their yellow bosoms almost touching, crests elevated, and beating the branch with their wings, scream their loudest notes in concert—­a confused jubilant noise that rings through the whole plantation.  Their joy at meeting is patent, and their action corresponds to the warm embrace of a loving human couple.”

Of the red-breasted marsh-bird (Leistes superciliaris) Hudson (Argentine Ornithology, vol. i, p. 100) writes:  “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 his 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