The great body of these birds retire, on the approach of summer, from the Rio Negro valley, a few only remaining to breed. Their nesting-habits and eggs are like those of the Picazuro.
[359.] ZENAIDA MACULATA (Vieill.).
(SPOTTED DOVE.)
Zenaida maculata, Burm. La-Plata Reise, ii. p. 497; Scl. et Salv. Nomencl. p. 132; iid. P. Z. S. 1868, p. 143 (Buenos Ayres); Durnford, Ibis, 1877, p. 193 (Buenos Ayres); Gibson, Ibis, 1880, p. 8 (Buenos Ayres); White, P. Z. S. 1882, p. 626 (Catamarca); Barrows, Auk, 1884, p. 275 (Entrerios).
Description.—Above pale brown; nape plumbeous; outer wing-coverts and scapularies with a few black spots; wings dark grey, with fine white margins; tail plumbeous, broadly ended with white, and crossed by a subapical black band; middle rectrices like the back: beneath pale vinaceous, brighter on the breast, and whiter on the throat; bill black; feet yellow: whole length 9·0 inches, wing 5·5, tail 3·5. Female similar.
Hab. South America, from the Amazons to Chili and Buenos Ayres.
This is the commonest species of the Pigeon tribe in the Argentine country, and is known to every one as the Torcasa, probably a corruption of Tortola, Turtle-Dove. In autumn they often congregate in very large flocks, and are sometimes observed migrating, flock succeeding flock, all travelling in a northerly direction, and continuing to pass for several consecutive days. But these autumnal migrations are not witnessed every year, nor have I seen any return-migration in spring; while the usual autumn and winter movements are very irregular, and apparently depend altogether on the supply of food. When the giant thistle has covered the plains in summer incredible numbers of Torcasas appear later in the season, and usually spend the winter on the plains, congregating every evening in countless myriads wherever there are trees enough to form a suitable roosting-place.
On bright warm days in August, the sweet and sorrowful sob-like song of this Dove, composed of five notes, is heard from every grove—a pleasing, soft, murmuring sound, which causes one to experience by anticipation the languid summer feeling in his veins.
The nest, as in other Pigeons, is a simple platform of slender sticks; the eggs are oval, white, and two in number. The birds appear to breed by preference near a human habitation, and do so probably for the sake of the protection afforded them; for the Chimango and other birds of prey destroy their eggs and young to a large extent.
One summer a Torcasa laid an egg in the nest of one of my Pigeons, built on the large horizontal branch of a tree at some distance from the dove-cote. The egg was hatched, and the young bird feared by its foster-parents; and when able to fly it took up its abode along with the other Pigeons. The following spring it began to separate itself from its companions, and would fly to the porch, and sit there cooing by the hour every day. At length it went away to the plantation, having, I believe, found a mate, and we saw no more of it.