(SILVER-BILL TYRANT.)
Lichenops perspicillatus, Burm. La-Plata Reise, ii. p. 457 (La Plata to Mendoza); Scl. et Salv. P. Z. S. 1868, p. 141 (Buenos Ayres); iid. Nomencl. p. 43; Hudson, P. Z. S. 1869, p. 432 (Buenos Ayres); Gibson, Ibis, 1880, p. 21 (Buenos Ayres); White, P. Z. S. 1882, p. 604 (Buenos Ayres); Barrows, Bull. Nutt. Orn. Cl. vol. viii. p. 141 (Entrerios, Azul).
Description.—Uniform black; primaries pure white, with black tips and bases; fleshy ring around the eye and bill yellow, feet black: whole length 5·6 inches, wings 3·5, tail 2·4. Female above dark brown, with light brown edgings to the feathers; remiges chestnut, with dark-brown tips; wing-coverts dark brown with fulvous tips; beneath fulvous white, breast with dark striations; under wing-coverts fulvous; bill yellowish, feet black.
Hab. Southern Bolivia, S.E. Brazil, Paraguay, Uruguay, La Plata, Chili, and Patagonia.
Naturalists have said a great deal about the well-known Silver-bill (the most important member of my “Spectacular” group), the question as to whether the black and red birds are sexes or two distinct species having long remained unsettled. Azara, writing in the last century, under the heading Pico de Plata, rightly described the red bird as the female of the black; but, unfortunately, in another part of his work he described the female again as a different species, naming it Suiriri chorreado. Darwin also separated the sexes, and gave the name of Lichenops erythropterus to the red-plumaged bird. The following extract gives only a portion of his argument, and is interesting to read, even now, when the question has been finally set at rest, as it shows how much the two birds differ:—“The tail of L. erythropterus is squarer and contains only ten feathers instead of twelve: the wing is 4⁄10 of an inch shorter; and the secondaries relative to the primaries are also shorter. The red colour on the primaries represents but does not correspond with the white on the black feathers of L. perspicillatus; and the secondaries in the two birds are quite differently marked. In L. erythropterus the third, fourth, and fifth primaries are the longest, and are equal to each other; the second is only a little shorter than the third. In L. perspicillatus the third is rather shorter than the fourth and fifth; and the second is proportionately shorter relative to the third, so that the outer part of the wing in this species is more pointed than in L. erythropterus. The outer claw in the latter species is only in a small degree straighter than in the former; and this, considering that L. perspicillatus is generally perched, and when on the ground can only hop, and that L. erythropterus feeds there entirely, and walks, is very remarkable.”
When one considers the habits of the two birds, even where they are most abundant and seen continually, it is indeed difficult to believe that they are of the same species. They are never seen associating together, even in the love-season, and when I have watched a pair actually engaged in constructing their nest, they appeared to keep as far apart as possible. More than that, the male, while unfriendly towards all other species, appears to cherish a special antipathy against the red bird; and when one comes near him never fails to pursue it with the greatest virulence from the neighbourhood. He is also strictly solitary, but the red birds frequently unite in small parties, especially in autumn, when I have often seen as many as a dozen together.
Altogether the Silver-bill has been a puzzle in the past, and it would now appear, from some recent observations made by Mr. Barrows, that we have not yet got to the end of all the curious points in its habits. Without doubt it is migratory. Its range extends from Paraguay to Patagonia, where it is not common. In Paraguay and the hotter parts of the Argentine country it is probably stationary; in Buenos Ayres, where it is most abundant, many individuals remain all the year in sheltered places, and the migration appears to become more definite the further south we get. Mr. Barrows travelled south across the pampas in the autumn, and says:—“The species was met with at all points visited, but south of the Azul not a single male in the black plumage was seen, though the brown birds (presumably females or young) were met with almost every day for nine weeks, and frequently in large numbers. Of course I began to suspect that the males must moult into a brown suit after nesting, as do our Bobolinks and many other birds, but I shot specimens at various times, and all proved to be either females or young males, and as I was confident that at Concepcion black males were to be found through the year, I was at a loss for an explanation, and am so still.”
The male Silver-bill is entirely black, there is nothing in nature blacker than its plumage; and, to enhance the effect, the beak is of a very delicate primrose-yellow, which at a little distance appears white, hence the vernacular name. The eye, and broad free skin surrounding it, which is ruffed like an Elizabethan collar, are of the same faint primrose hue. The secondary wing-quills are pure white, but the white is only displayed when the bird flies. The female has the naked skin encircling the eye, but its colour, as also that of the beak, is much darker than in the male. Entire upper plumage dark brown; secondaries chestnut; lower parts fawn-colour, marked with brown. The young males are at first like the females in colour, and do not acquire the black plumage until the end of the summer.
The bird ranges over the whole of the Argentine Republic, and, according to Gay, is also common throughout Chili, where it is known as the Colegial (Collegian or learned person), on account of its stiff grave manner, black dress, and spectacled appearance.
The male is a solitary bird, and feeds chiefly on the ground, running rapidly about in open places like a Muscisaxicola. It is also frequently seen perched conspicuously on the summit of a tall stalk or bush, and occasionally making a dart into the air after passing insects, showing in this habit his relationship with the Tyrant-birds. But he perches on an elevation less to watch for insects than for the purpose of his curious spectacular performance. This highly eccentric habit is strikingly like that of Cnipolegus hudsoni; and I have no doubt that all the Cnipolegi possess similar habits. Both birds perch on a conspicuous place, upright, motionless, and looking more like grotesque little automata than living things; they both also leave the perch suddenly, as if shot from it by means of a steel spring. This singularly sudden movement, and the motion of the wings, rapid as in the Humming-bird, or shut and opened alternately and exhibiting the white wing-colour in a series of flashes, seems related to the conspicuous white mark. In both species, also, the wings make a humming sound during flight. The motions of the Silver-bill are, however, in some respects different from those of the Cnipolegus. Springing from its perch at intervals, it darts vertically to a height of about fifteen yards, then turns a summersault, uttering at the same moment a shrill-sounding little cry, after which it drops down again and alights on its perch suddenly, as if jerked back to it, and there remains stiff, erect, and motionless as before.