Fig. 114.–Wren. Troglodytes parvulus. × 4⁄7.
Wrens frequent marshy, as well as dry or rocky localities, being familiar and yet wary; they habitually hop about with upturned tails, fly sharply from cover to cover, and hunt for insects, their larvae, and spiders, among fallen leaves, in crevices of rocks, and so forth, while they occasionally eat worms, small molluscs, crustaceans, and seeds. The characteristic note is shrill and Warbler-like, though harsher sounds accompany it, but Cyphorhinus cantans, the Organ-bird of the Amazons, Troglodytes domesticus (aedon), Microcerculus, and other American forms utter melodious flute-like strains. The nest is usually a domed structure of ferns, grass, moss, leaves, or even twigs, often lined with hair or feathers, which is placed in bushes, hedges, cacti, reeds, and cavities of masonry, or on trees, rocks, banks, and the like; Salpinctes, Catherpes, Urocichla and sometimes Pnoëpyga make no covering; Campylorhynchus fashions a large purse-like structure, with a long passage for entrance. The eggs vary in number from three to nine, and are white, with or without spots or freckles of red, purplish, or brownish; in Thryophilus pleurostictus they are said to be blue.
Fam. X. Chamaeidae.–This contains only Chamaea fasciata and C. henshawi of California, which by various American authorities have been referred to the Wrens or the Tits, though not agreeing closely with either. This is the only Family of land birds peculiar to the Nearctic Region. In both sexes the lax plumage is brown above and buffish below, with faint tail-bars and pectoral streaks; the bill is short, straight, and compressed, and is furnished with rictal bristles; the metatarsi are stout and nearly smooth; the wings are rounded and concave; the tail is graduated. Chamaea inhabits dry plains and bushy hill-sides, flits about or searches for insects with elevated tail, utters a Wren-like trill, and builds a nest of twigs and grass in low bushes, adding hair or feathers to the lining, and laying three or four pale greenish-blue eggs.
Fam. XI. Hirundinidae.–The Swallows and Martins compose a well-defined cosmopolitan Family, certainly far removed from the Swifts (p. [420]), with which they used to be joined. The latter have ten tail-feathers, and hardly any scutellation on the legs, the former twelve rectrices, and an anteriorly scutellated metatarsus. The bill is short, broad, and usually much depressed, being notched at the tip and split nearly to the eyes. The feet are very small and weak, with the middle digit more or less adherent to its neighbours; Tachycineta has a stoutish hallux, Chelidon feathered toes, and Cotile riparia a tuft at the back of the metatarsus. The wings are extremely long and pointed, while the exterior margin of the outer primary has hooked barbs in the males of Psalidoprocne and Stelgidopteryx. The tail varies in length, and is often very deeply forked, Petrochelidon, Stelgidopteryx, Chelidon dasypus and Psalidoprocne nitens having it exceptionally square; while the lateral feathers may be almost linear, as in Hirundo rustica, or even wire-like, as in H. smithii.
Chelidon is purplish- or bluish-black, or brown, having a white rump occasionally barred with black, and white or buffish under parts; Tachycineta is similar, or greener and somewhat bronzy, in certain cases lacking the white rump, in others shewing white mottlings above. Hirundo is glossy metallic black, with a variable amount of chestnut or rufous on the head, rump, or lower surface; the last of these regions exhibiting much white or having a black pectoral band, while streaky markings are not uncommon. Cheramoeca is blue, black, white, and brown above, and white below with a black breast-patch; Procne is either entirely blue-black or has some white beneath, P. tapera alone being brown, with a longitudinal band of the same colour on the white lower surface. Atticora is blue-black or greenish above, black and white or brown underneath; Petrochelidon is steel-blue with concealed white striations, the forehead, nape, rump, and most of the lower surface being chestnut, rufous, or buff, with or without stripes; Psalidoprocne is uniform blue, green-black, or sooty, P. albiceps having a white crown and chin. Cotile, Phedina, and Stelgidopteryx are dull brown above, the first being white, grey, brown, or rufous below, the second white with longitudinal brown streaks, and the third white and rufous with yellow middle to the breast and abdomen in two species. The plumage of most Swallows is very metallic, and white spots are often prominent on the tail feathers in Hirundo, Chelidon, Cotile, and Petrochelidon. The female is duller than the male in Procne only.
The range of Hirundo and Cotile is practically worldwide, reaching from beyond the Arctic Circle in summer to South Africa, India, and Brazil in winter, not to mention resident southern species; no Swallow, however, occurs in New Zealand, nor is Cotile found in the Australian Region. Four species of Petrochelidon are found in America, two in Southern Africa, two in the Australian Region, and one in India–a remarkable distribution. Psalidoprocne, Phedina, and Cheramoeca are Ethiopian, Mascarene (with Madagascar), and Australian respectively: Tachycineta and Procne extend over the New World from its Arctic portions to Patagonia, Atticora from that country to Guatemala, Stelgidopteryx from Canada and British Columbia to Bolivia and Brazil. Chelidon is confined to the Old World, migrating in autumn to Central Africa, Borneo, and Burma. The summer migrants to Britain are Hirundo rustica, the Swallow, Chelidon urbica, the Martin, and Cotile riparia, the Sand-Martin. Swallows traverse immense distances on their periodical journeys, while all perhaps shift their quarters to some extent for the winter.
Fig. 115.–Swallow. Hirundo rustica. × ½.
Hardly any sort of country comes amiss to these birds, though the neighbourhood of water is preferred, and for some species seems necessary. Spending their life chiefly in the air and alighting comparatively little, they rapidly dart, twist, double, sail aloft, or skim the water's surface in company, at times chasing each other in sport or even fighting savagely. Insects, which form the whole of their sustenance, are habitually taken on the wing, and the young are sometimes fed, or building materials snatched up, in full flight. A few species not uncommonly perch on trees, as Hirundo rustica, Tachycineta albiventris, Petrochelidon nigricans, Psalidoprocne nitens and Procne tapera; the last-named, moreover, is exceptional in being non-gregarious, while it flits about with depressed wings and slow butterfly-like flight when not hawking. The majority are rarely seen on the ground, unless they are procuring mud for nidification; but many roost on reeds or in their nests, and just before migration they settle in crowds on branches, fences, wires, and ridges of roofs. Hirundo, Chelidon, and Psalidoprocne bask in the sun on gravelly places. The twitter or warble of Swallows–uttered on the wing or at rest–and their squeaks of anger or alarm, are well-known; the scream of Procne and the chirp of Stelgidopteryx being somewhat exceptional; when excited, however, the bill is not uncommonly snapped noisily. The nest may be cup-shaped as in our Swallow, Cotile rupestris, C. fuligula, and C. concolor, and made of agglutinated pellets of mud with a lining of straw, chaff, leaves, or feathers; it may be similarly constructed but semi-ovate, with a hole near the top, as in the Martin; or retort-shaped with a tube for entrance at the side, as in several members of the genera Hirundo and Petrochelidon: in these cases it may be placed inside buildings, under eaves, against rocks or walls. Procne–when not accommodated with a box–some species of Tachycineta, Petrochelidon nigricans, and other forms, not uncommonly prefer holes in trees, lining them as usual, if at all; while many species of Cotile, Psalidoprocne, and Cheramoeca tunnel in banks, or, more rarely, choose holes in masonry. Procne furcata utilizes the holes of Conurus patachonius; P. tapera the nests of Furnarius rufus in Argentina; Tachycineta leucorrhous occasionally that of Anumbius; Atticora cyanoleuca that of the Dendrocolaptine Geositta, itself within that of a biscacha. The eggs are from four to seven in number, generally pure white in Martins, and whitish with reddish-brown, grey, and lilac markings in Swallows; but the cases are occasionally reversed. Two or even three broods are reared in a season, and tended with the greatest care. Colonies are frequently formed, especially by Bank- and Cliff-Swallows. In Britain the Sand-Martin arrives first, but the Swallow comes early in April, while individuals have even been obtained in winter.
Fam. XII. Campephagidae.–The "Cuckoo-Shrikes" are commonly placed near the Laniidae, but are possibly connected with the Muscicapidae or the Corvidae. The bill is usually strong, and of moderate length, being hooked, arched, and wide at the base; it is especially stout in Artamides, decidedly weaker in Campephaga, long and thin in Edoliisoma. The metatarsus may be elongated and comparatively robust as in Pteropodocys, Lalage, and Symmorphus, or short and less powerful, as in Pericrocotus; the wings are normally long and pointed, and more particularly so in Pericrocotus, Lalage, Symmorphus, and Graucalus. The tail is also fairly long, and frequently rounded, though it may be forked, as in Pteropodocys, and to a less extent in Campechaera, or graduated as in Pericrocotus, Campephaga, and Graucalus. The plumage is soft, with characteristically stiff shafts on the lower back; the nostrils are nearly concealed by the feathers; the rictal bristles are feeble. The usual coloration is either bluish-grey with a certain amount of black and white, or chiefly black and white. The black has generally a purplish or a greenish gloss; while barring occurs occasionally in the cocks, and much more commonly in the hens, where the tints are duller, the grey lighter, and the hue in some cases brown or even rufous. The Mascarene Oxynotus is almost unique among Birds in having the males of the two species alike, the females very different. Shaft-streaks on the feathers are fairly frequent; two species of Lalage have a chestnut lower surface, and one the rump similar; while Symmorphus is either brown above and whitish below, or black and white with buff rump and under parts. Campechaera is green and golden-yellow in both sexes, but shews some black, white, and grey as well; Lobotus is olive-yellow with dark green head and throat, orange-chestnut rump and breast, greenish tail, and an orange lobe at the gape. Pericrocotus is usually black, adorned with lovely scarlet, crimson, orange, or yellow markings, and with a little white, but two species lack the brilliant tints, and others replace the black by brown or grey; the females in this genus usually have yellow where the males have red, though they also shew red in two cases. Three African species of Campephaga vary from the ordinary grey or blackish coloration in being glossy bluish-black, with scarlet, orange, and yellow shoulder-patches respectively, and one in being steel-green, with purple face and neck, and steel-blue lower surface. In these forms the females have yellow markings. Finally, Graucalus azureus is azure and black, with a shade of cobalt.