The Marsh-Wren has a sweet and delicate song, resembling that of the House-Wren (Troglodytes furvus), but much less powerful. It does not migrate; and on the pampas I have heard it singing with great animation when the pampas-grass, where it sat perched, was white with frozen dew. Probably its song, like that of Troglodytes furvus, varies in different districts; at all events, the pampas bird does not possess so fine a song as Azara ascribes to his “Todo Voz” in Paraguay, which is undoubtedly the same species.
[ Fam. V. MOTACILLIDÆ, or WAGTAILS.]
The Wagtails and Pipits are closely-allied forms, and are usually referred to the same family of Oscines. The Wagtails are restricted to the Old World, although it has been recently ascertained that some of them occasionally occur as stragglers in the northern latitudes of America. Of the almost cosmopolitan Pipits about eight or nine species are sparingly distributed over the prairies and pampas of the New World. One of these is a common resident in the pampas of Argentina, and another (perhaps somewhat doubtful species) is occasionally met with.
[15.] ANTHUS CORRENDERA, Vieill.
(CACHILA PIPIT.)
Anthus correndera, Scl. et Salv. Nomencl. p. 8; Hudson, P. Z. S. 1873, p. 771 (Buenos Ayres); Durnford, Ibis, 1877, p. 32 (Chupat), p. 168 (Buenos Ayres), 1878, p. 392 (Central Patagonia); Sclater, Ibis, 1878, p. 362; White, P. Z. S. 1882, p. 594 (Buenos Ayres); Döring, Exp. al Rio Negro, Zool. p. 37 (Azul); Barrows, Bull. Nutt. Orn. Cl. viii. p. 87 (Concepcion, Entrerios); Sharpe, Cat. B. x. p. 610. Anthus rufus, Burm. La-Plata Reise, ii. p. 474 (Mendoza, Paraná); Durnford, Ibis, 1876, p. 158.
Description.—Above pale sandy buff, mottled with black centres to the feathers; wing- and tail-feathers dark brown, edged with buff, the penultimate tail-feather with a white tip, the outer tail-feather almost entirely white; neck and breast sandy buff, with large triangular black spots; flanks buff, streaked with black; abdomen and under tail-coverts isabelline; bill dusky grey; feet pink: total length 6·0 inches, wing 2·9, tail 2·3. Female similar.
Hab. Paraguay, Argentina, Patagonia, and Chili.
Azara’s only reason for calling this bird La Correndera was because he thought it resembled a Tit-Lark known by that name in his own country, but of which he merely had a confused recollection. It is therefore to be regretted, I think, that correndera has been adopted as a specific name by naturalists instead of “Cachila,” the vernacular name of the bird, familiar to every one in the Argentine country. Azara’s Spanish bird was probably Anthus pratensis, which closely resembles A. correndera in general appearance, and has, moreover, as wide a range in the northern as the last-named species has in the southern hemisphere. In the volume on Birds in the ‘Voyage of the Beagle,’ it is said that a species of Anthus ranges further south than any other land-bird, being the only land-bird found on Georgia and South Orkney (lat. 61° S.).
In colour and language, possibly also in size, the Cachila is variable. It is a very common bird, widely and plentifully distributed over the pampas, found alike on marshy and dry grounds, but rare in the region of giant grasses. While abundant, it is also very evenly dispersed, each bird spending its life on a very circumscribed plot of earth. Those frequenting marshy or moist grounds are of a yellowish-cream colour, thickly mottled and striped with fuscous and black, and have two narrow parallel pure white marks on the back, very conspicuous when the bird is on the ground. The individuals frequenting high and dry grounds are much paler in hue, appearing almost grey, and do not show the white marks on the back. They also look larger than the birds on marshy lands; but this appearance is probably due to a looser plumage. The most strongly-marked pale and dark-plumaged variations may be found living within a few hundred yards of each other, showing how strictly each bird keeps to its own little “beat”; for this difference in coloration is, no doubt, due entirely to the amount of moisture in the ground they live on.