(RED-BACKED TYRANT.)
Centrites niger, Burm. La-Plata Reise, ii. p. 458; Scl. et Salv. Nomencl. p. 44; Durnford, Ibis, 1878, p. 395 (Chupat); White, P. Z. S. 1882, p. 604 (Buenos Ayres); Döring, Exp. al Rio Negro, Zool. p. 42 (R. Colorado); Barrows, Bull. Nutt. Orn. Cl. viii. p. 142 (Entrerios, Pampas).
Description.—Above and below deep black: whole of back except the rump and scapularies chestnut; bill and feet black; under wing-coverts and wings below black: whole length 5·0 inches, wing 2·8, tail 1·9. Female above brown, back fulvous red; tail black; below ashy brown.
Hab. Patagonia, Chili, and Argentina.
The little Red-backed Tyrant comes nearest to Muscisaxicola mentalis in habits, but does not perch on bushes and trees, and is less gregarious than that bird. It is the smallest of all those varied members of the Tyrannine family which have abandoned forests and marshes and the pursuit of insects on the wing, to live on the wintry uplands of Patagonia, and on the sterile plains bordering on the Andes.
The male is only five and a quarter inches long. The entire plumage of the male is intensely black, except the back, which is bright chestnut. The inside of the mouth and tongue are vivid orange-yellow. The chestnut colour on the female is pale, the rest of the plumage grey, except the quills, which are dark.
Its summer home is in the southern portion of Patagonia, but its nesting-habits are not known. In March it migrates north, and is very common everywhere on the pampas throughout the winter. They arrive in small parties of three or four, or in little loose flocks of about a dozen individuals, travelling with a swift low flight. Males, females, and young, grey like the last, arrive together; shortly after arriving the young males become mottled with black, and before leaving acquire the adult plumage. They appear to leave in spring all together, but from a note by Durnford it would appear that the males travel in advance of the females. He says:—“Males of this species were common at Chupat throughout September and during the first few days of October. On the 5th of the latter month I observed the first females, which gradually increased in number.”
The Little Red-backs inhabit open unsheltered plains, and have so great a predilection for bare ground on which they can run freely about, that on their arrival on the pampas, where the earth is thickly carpeted with grass, they are seen attaching themselves to roads, sheep-pens, borders of streams, vizcacha villages, and similar places. They are exceedingly restless, running swiftly over the ground, occasionally darting into the air in pursuit of small flies, and all the flock so scattered that there will be a dozen yards between every two birds. Mr. Barrows describes their lively habits very well:—“I think this is one of the most restless birds I ever saw. You cannot depend upon him to be in the same place two consecutive half-seconds. He runs like a Sanderling, and whenever he keeps his feet still by accident, his wings are flirted in a way that shows his anxiety to be off. Several are usually found together, and sometimes a loose flock of a hundred or more is seen. They are very strong on the wing, sometimes mounting rapidly for several hundred feet, if suddenly startled, and after a few moments spent in circling like a Snipe, they drop again almost as suddenly as a shot, and as if from the very clouds.”