Fig. 105.–Nest of Oven-bird (Furnarius). × ⅕.
The habits are extremely diverse. Geositta cunicularia flits along low and swiftly, like a Wheatear, with the tail in motion, or crouches and runs before the pedestrian, uttering a note resembling piti-piti, varied by a ringing trill. It frequents bare spots, and bores oblique tunnels in biscacha burrows, sandy banks, or mud walls, ending in cavities lined with soft grasses, where it lays five white eggs. The food consists of seeds, insects, and their larvae, the bill being commonly used to dig. Lochmias nematura fills a similar hole with a large-domed nest of twigs and roots, lined with leaves, which contains two white eggs. The Oven-birds (Furnarius) run or hop unconcernedly among the wayfarers with the head thrown back, or pause with one foot uplifted; they utter incessant and loud, but not unmelodious, cries with the beak outstretched, which are even heard at night.[[274]] Worms, insects and their larvae are sought upon the ground, and both sexes incubate, the pairs keeping together throughout the year. The curious nest (Fig. 105) is placed in exposed situations on branches, in forks of trees or shrubs, on posts, rocks, or house-roofs; it has thick walls, almost unbreakable when dry, of clayey mud and dung mixed with a little hair or dry grass, a lining of the same materials underlying the three to five white eggs. This massive structure has an inner chamber with an outer passage running partly round it, and is generally the work of several months, the materials being only procurable in damp weather. The above refers at least to Furnarius cinnamomeus, F. minor, and F. rufus (the "Hornero" or Baker); but White[[275]] states that F. figulus builds a stick nest, and E. Bartlett[[276]] that F. torridus deposits four creamy white eggs on twigs and bents in holes in banks. Upucerthia, resembling Geositta in general habits, ranges to an altitude of nine thousand feet. The lively Cinclodes recalls both the Wheatear and the Dipper, as it runs with upturned tail from stone to stone, takes short, low flights, or hunts for crustaceans, molluscs, and insects in the water, equally happy on the streams of the Andes, or the desolate lake-sides of Patagonia. The note is a sharp trill, while three white eggs are laid on a bed of grass and fur in holes. Sclerurus frequents damp forests, scratching among the leaves, and crouching, when startled, on some trunk. Phloeocryptes flies weakly, but hops actively about reed-beds in pursuit of flies, uttering reiterated grating notes; it attaches its Wren-like nest of grass or rushes and mud, lined with feathers, moss and hair, to a few of the reed-stems, and builds a projection over the entrance. The two or three oval eggs are glossy blue. The shrill-voiced Leptasthenura clings to the branches in search of insects like a Tit, and lays from three to six pointed white eggs on soft materials in holes in trees, sometimes utilizing nests of Furnarius rufus, Siptornis sordida, and other species. Synallaxis, usually seen in pairs searching for food upon the bushes, has a persistent harsh double call or a cat-like cry; it forms a loose, oval structure, which would fill an ordinary wheel-barrow, of thorny sticks and twigs in forks of trees, lining it with hair, feathers, woolly leaves,and the like, and often capping it with more leaves. This generally possesses a lower chamber connected by a vertical or horizontal passage with the entrance, itself protected by a tubular fabric; while more than one nest is often found in the same tree. The three or four eggs are pale greenish-blue or whitish. Siptornis sordida appears to have similar habits, but several of its congeners run like mice; or conceal themselves in herbage or holes, the marsh-loving species uttering very whirring notes. S. sulphurifera fabricates a domed nest of grass among rushes, and lays two white eggs; that of S. maluroïdes is open, and lined with feathers and wool, though the site is similar; that of S. striaticeps resembles the last-mentioned, but is placed in a tree-fork and contains four or five white eggs. S. hudsoni arches the grass over a hollow in the ground in open spots, and deposits five pale buff eggs on a little powdered dung; its flight is Pipit-like, and its cry melancholy. Phacellodomus, usually found in hot dry valleys, is sluggish, and has a shrill, harsh voice; the nest, containing four white eggs, being hung from the end of a branch, and recalling that of Synallaxis. Xenops, Sittosomus, Picolaptes, Xiphorhynchus, Pseudocolaptes, and many other forms are denizens of damp forests, and run up the tree-trunks spirally like Creepers, searching for prey and tapping the bark as Woodpeckers do; the cries are plaintive or noisy, and the white eggs, apparently two in number, are laid in holes. Large insects are sometimes battered upon the branches. Anumbius acuticaudus, the "Thorn-bird" or "Firewood Gatherer," makes a bulky nest some two feet high of thorny sticks, and places it in isolated trees. From an entrance near the top a spiral or zigzag passage leads to a lower cavity lined with grass, hair, feathers, and wool, where five pointed white eggs are deposited; while sometimes an upper roosting chamber is added. This bird utters ticking chirps or trills, and feeds mainly upon the ground, regaining the branches with difficulty. Homorus lophotes, the "Cachalote," with its strikingly white eyes and blue beak, haunts plains with scattered trees or bushes, being decidedly shy and quick of foot, though weak of flight; it eats insects, and turns up the earth with its bill or claws. Rasping cries are often emitted in concert; while the nest–even larger than that of Anumbius–is a loose mass of similar structure, placed on some low branch or in a bush, the three or four white eggs occasionally shewing through the bottom. Drymornis, again, has Woodpecker-like habits, whereas Limnornis and Limnophyes creep about dense reed-beds, and only appear now and then to utter jarring or chattering sounds.
Fam. X. Formicariidae.–The so-called "Ant-birds"–not known to live on ants–are plentiful in the forests of northern South America, whence the numbers decrease to Central America, Chili and Argentina. Of the two hundred or more species none inhabit the Antilles, but three occur in Trinidad and one in Tobago. Mr. Sclater[[277]] allows as provisional Sub-families the strong Thamnophilinae, the weaker Formicariinae, and the long-legged Grallariinae.
The beak is strong, compressed, hooked, and terminally toothed in the Thamnophilinae, being exaggerated in Batara, large and swollen in Cymbilanius, and exceptionally hooked in the former genus and Pygoptila; Cymbilanius, Neoctantes, and Clytoctantes have the genys upturned. In the Formicariinae the bill is weaker and but slightly hooked, being very long and thin in Rhamphocaenus; in the Grallariinae it is usually elevated and compressed, though broad in Pittasoma. The taxaspidean metatarsus (p. [471]) is moderate or short in the Thamnophilinae, and remarkably long in the Grallariinae, where it may be very strong, as in Pittasoma; among the Formicariinae it is short and thick in Rhopoterpe and Formicivora, long and thin in Psilorhamphus and Formicarius, and so forth. In Phlogopsis, Psilorhamphus, Rhamphocaenus, Heterocnemis, Myrmeciza, Hypocnemis, Pithys, and Gymnopithys the scutes are nearly fused. The outer and middle toes are joined towards the base. The wings, which have ten primaries and nine secondaries, are normally short and rounded, though longer in Rhopoterpe; the tail is commonly long and broad in the Thamnophilinae, varies greatly in the Formicariinae, and is very short and square in the Grallariinae. It may be rounded or graduated in the first two Sub-families, and Terenura has it remarkably thin; Cercomacra, Formicivora caudata, and F. ferruginea have only ten rectrices in place of the usual twelve. Thamnomanes has well-developed rictal bristles, Rhamphocaenus has the nostrils in a groove and partly covered by a membrane.
The sexes are similar, and mainly reddish-brown, in Rhamphocaenus, Phlogopsis, and the Grallariinae; but generally the males are black and white, black, grey and brown, or uniform black; and the females ferruginous, more or less relieved by black and white. Cross-bars, spots, and striations are not uncommon, the white often shewing as a band on the tail, an edging to the wing-coverts, or exceptionally, as in Pygoptila margaritata, as round spots on both wing and tail; while the yellowish lower parts of Myrmotherula pygmaea, Herpsilochmus rufimarginatus and three species of Terenura exhibit the brightest tints found in the Family. Black or dark-hued caps are not infrequent; crests occur in Batara, Pithys, and many members of Thamnophilus; the rump-feathers are often dense and elongated, as in Thamnistes, Pygoptila, Chamaeza, Cercomacra, and Thamnomanes; those of the flanks are much developed in Thamnocharis; those of the lores are short and erect in Pyriglena. Bare red or bluish orbits are found occasionally; Gymnocichla has most of the head naked and blue; and the irides may be red, white, or brown. Batara is quite fourteen inches long, Myrmotherula pygmaea about three.
The usually shy and retiring Formicariidae either skulk among dense undergrowth in hot tropical forests, or frequent more cultivated districts; they creep about silently, singly or in pairs, seeking spiders, insects and their larvae, on the twigs and foliage of trees, or on parasitical plants or grasses; while they habitually keep near the ground, though sometimes joining flocks of other birds in their higher flights. Many carefully search the lower surface of the leaves for food with the head downwards, and occasionally eat seeds. The Grallariinae appear to be entirely, and the Formicariinae to a great extent terrestrial, hops being the characteristic mode of progress; the tail is commonly carried erect or in motion, as in the case of Formicarius, and is often much abraded by the thorny thickets. Thamnophilus albinuchalis and some other species choose dry situations, but generally the vicinity of water is preferred. The ordinary note in the Family is deep and powerful, and is said to have the effect of ventriloquism; it consists of monotonously repeated sounds, like ke-ke-ke or ko-ko-ko, varied by more rasping tones or trills. The nest, a slight shallow structure, generally hung from the lower twigs of a tree or bush, is composed of straws, fibres, roots, and hair, or occasionally of leaves, moss, and wool; it contains two or three white, bluish, or rufous-brown eggs, usually spotted, streaked, or zigzagged with red-brown, but more rarely with grey.
Fam. XI. Conopophagidae.–These curious birds, and their equally remarkable allies the Pteroptochidae, differ from all other Passeres in having two incisions posteriorly on each side of the sternum. The Conopophagidae, extending from Colombia to Bolivia and Brazil, include the genus Conopophaga, and probably Corythopis. The head is large, the bill depressed in the first-named, longer and more compressed in the last; the exaspidean metatarsus (p. [473]) is thick and long in the one, with broad curved hind-claw, but is thinner, with straighter and weaker hallux, in the other. The outer and middle toes are basally connected. The wings are moderate and rounded, as in the next Family; the tail is very short in Conopophaga, which has long, lax rump-feathers. The general coloration is brown, with a white mark behind the eye in the last-named genus; the head may be black, or chestnut with black sides; the throat black; the breast banded with chestnut, black or grey; or the central abdomen white. Corythopis has black striations below.
Fam. XII. Pteroptochidae.–This group ranges from Costa Rica to Patagonia, occurring up to an altitude of nine or ten thousand feet. The bill is comparatively long and thin in Scytalopus and Merulaxis, stronger in Liosceles, Pteroptochus, Hylactes, and Rhinocrypta, being much arched in the last-named; the culmen expands into a peculiar oval plate in Acropternis and Triptorhinus; while a membrane partially covers the nostrils. The taxaspidean metatarsus (p. [471]) is generally elongated and strong, with long claws, the hallux being long and incurved in Hylactes, and similar but straighter in Acropternis; the whole foot is shorter in Rhinocrypta, more slender in Pteroptochus, while the scutes are fused in front in Liosceles. The short, rounded wings have ten primaries and eight secondaries; the tail varies in length, and may be graduated, as in Merulaxis and Acropternis, or short and more even, as in Triptorhinus. Hylactes has fourteen rectrices in place of twelve. The colour is blackish, dark grey, or brown, often barred or scalloped with black; the crown, rump, breast, or belly are at times chestnut or rufous, the lower parts varied with white, or even banded with orange. Merulaxis has long, stiff loral plumes, Rhinocrypta lanceolata a crest, and several forms elongated rump-feathers. In Acropternis the back and abdomen are ocellated with white. The sexes are nearly similar.
These peculiar birds are commonly shy and retiring, hopping actively about with erect tails, or running like mice, but rarely flying, except between the boughs and the ground. They are decidedly difficult of observation, though they follow up the pedestrian under cover, betraying their position by their scolding cries. Many species, such as Hylactes tarnii, the "Guid-guid," Pteroptochus rubecula, the "Cheu-can," and Triptorhinus paradoxus, the "Cheu-gui," inhabit damp, gloomy forests; others often frequent dry plains, or stony and bushy hill-sides, as H. megapodius, "El Turco," and P. albicollis, the "Tapaculo"; while Scytalopus magellanicus prefers thick woods, but also haunts grass-lands in the Falkland Islands. Rhinocrypta lanceolata, the "Gallito," or Little Cock, lives in thickets and hedges, and struts in the open like a Fowl. The food, chiefly obtained upon the ground, consists of insects, seeds, and buds. The noisy and generally harsh notes vary considerably, Hylactes tarnii yelping like a dog, Pteroptochus albicollis sometimes uttering a sound like a coo, Triptorhinus paradoxus a reiterated frog-like croak, Rhinocrypta lanceolata a hollow chirrup or a scolding cry. The nest, commonly situated near the ground, is said in some cases to be made of sticks; Rhinocrypta forms a domed structure of grass in a bush, and lays four eggs; Scytalopus magellanicus is recorded as using a mass of moss upon a bank to contain its set of two; Hylactes and Pteroptochus are reported to nest in burrows. The eggs are white, at least in the first three.