WARBLER, in ornithology, the name bestowed in 1773 by Pennant (Genera of Birds, p. 35) on the birds removed, in 1769, by Scopoli from the Linnssan genus Molacilla (cf. WAGTAIL) to one founded and called by him Sylvia, —the last being a word employed by several of the older writers in an indefinite way,—that is to say, on all the species of Molacilla which were not Wagtails. " Warbler " has long been used by English technical writers as the equivalent of Sylvia, and consequently generally applied to all members of the Family Sylviid.se thereon raised, which has since been so much subdivided as to include a vast number of genera, while species almost innumerable have from time to time been referred to it.

Until recently ornithologists had come to agree pretty well as to which forms should he considered to belong to the Family Sylviidm, —the '' American Warblers " (Mniotiltidm), to be presently con-sidered, being therefrom segregated ; but some writers, seeing the difficulty of separating the remainder from the Turdidm (cf. THRUSH), tried to get over it by proposing to erect an intermediate Family for the WHEATEAR (q.v.) and some similar forms, under the name Saxicolidm. In truth the difficulty was thereby doubled, for, if it was before hard to distinguish between Sylviidm and Turdidm, it has since become harder to distinguish on the one hand between Sylviidm and Saxicolidm, and on the other between Saxicolidm and Turdidm. The confusion thus caused is chiefly due to the adoption in a more or less modified form of the views put forth by Sundevall in 1872, and revised by him in 1874 (cf. ORNI-THOLOGY, vol. xviii. p. 38). For him, however, it is to be said that he at least proceeded in a fashion that had long been recognized, and gave reasons, whether good or bad, for the system he pro-pounded; but his imitators have omitted so obvious a requirement, and leave to any one who would use their results the task of dis-covering how they have been reached. Hence it has been suggested that some of the alterations introduced since Sundevall's time have been purely arbitrary, if indeed they did not proceed from considerations of personal convenience, or occasionally even through mischance. Still the greatest allowance must be made for those who attempt to reduce to order such a multitudinous assemblage of forms—forms which present an almost endless variety of small differentiating characters, pointing in numerous directions—wdiile the essential structure of all is apparently so similar that at present there is no hope of assistance from the anatomist or the morphologist. But the affinity, seeming or real, to the Turdidse, does not otter the only difficulty. The resemblance, which some other forms, often placed with the Sylviiclse, bear to the Timeliidm —the Cratcropodidm of some systematists—is equally if not more puzzling. It is admitted by many systematists that the Timeliidm form a group that has been made a "refuge for the destitute," a group into which genera and species that were trouble-some to classify have been thrust; and, as a natural consequence, the limits of such a " Family" or group have scarcely been plausibly defined. It appears that the so-called Timeliidse lead off to other groups, as the Laniulm (cf. SHRIKE) and what not, and their existence as a separate "Family " can hardly be taken for a certainty. Again, a small group of birds, almost wholly peculiar to the Australian region, have been sometimes separated as Maluridm, and of these more must be said presently. Lastly, there are certain genera that, though formerly included without hesitation among the Sylviidm, have lately been designated " Fly-catchers," on grounds, however, that have not been explained.

To deal with this theme in satisfactory detail would require far more space than can here be allowed, for the failures of later systematists would have to be shewn by a series of minute criticisms of a kind that would be only acceptable to specialists, and hardly understood by others than experts. All things then considered, it would seem to be best for our present purpose to regard the " Warblers "—without pledging our faith to the recognition of a '' Family " Sylviidm—from the point of view which obtained before the more recent and perplexing (because ill-defined) opinions were introduced, and that aspect is afforded by the scheme furnished by Canon Tristram to Mr Wallace, and by him adopted in his Geographical Distribution of Animals (ii. pp. 257-260); but our limits will only allow us to touch upon a few of the most prominent members in addition to those which have already been or will form the subject of separate articles. In this sense then the first that may be mentioned are those forming a group of more or less aquatic habit, usually called Calamoherpines but more correctly Acroccpha-linm, the commonest of which in England is the well-known Sedge-bird or Sedge-Warbler, Acrocephalus schcenobmnus, whose chattering song resounds in summer-time from almost every wet ditch in most parts of Britain. As is the case with so many of its allies, the skulking habits of the bird cause it to be far more often heard than seen ; but, with a little patience, it may be generally observed flitting about the uppermost twigs of the bushes it frequents, and its mottled back and the yellowish-white streak over its eye serve to distinguish it from its ally the Reed-Wren or Reed-Warbler, A. streperus, which is clad in a wholly mouse-coloured suit. But this last can also be recognized by its different song, and comparatively seldom does it stray from the reed-beds which are its favourite "haunts. In them generally it builds one of the most beautiful of nests, made of the seed-branches of the reed and long grass, wound horizontally round and round so as to include in its substance the living stems of three or four reeds, between which it is suspended at a convenient height above the water, and the structure is so deep that the eggs do not roll out when its props are shaken by the wind. Of very similar habits is the Reed-Thrush or Great Reed-Warbler, A. arundinaceus, a loud-voiced species, abundant on the Continent but very rarely straying to England. Much interest also attaches to the species known as Savi's Warbler, A. luscinioides, which was only recognized as a constant inhabitant of the Fen-district of England a few years before its haunts were destroyed by drainage. The last example known to have been obtained in this country was killed in 1856. The nest of this species is peculiar, placed on the ground and formed of the blades of a species of Glyceria so skilfully entwined as to be a very permanent structure, and it is a curious fact that its nests were well known to the sedge-cutters of the district which it most frequented, as those of a bird with which they were unacquainted, long before the builder was recognized by naturalists. In coloration the bird somewhat re-sembles a Nightingale (wdience its specific name), and its song differs from that of any of those before mentioned, being a long smooth trill, pitched higher but possessing more tone than that of the Grass-hopper- Warbler, A. nsevius—the Salicaria locustella of many authors —which is a widely-distributed species throughout the British Isles, not only limited to marshy sites, but affecting also dry soils, in-habiting indifferently many kinds of places where there is tangled and thick herbage, heather, or brushwood. In those parts of England where it was formerly most abundant it was known as the Reeler or Reel-bird, from its song resembling the whirring noise of the reel at one time used by the spinners of wool. The precise determination of this bird—the Grasshopper Lark, as it was long called in books, though its notes if once heard can never be mistaken for those of a grasshopper or cricket, and it has no affinity to the Larks—as an English species is due to the discernment of Gilbert White in 1768. In its habits it is one of the most retiring of birds, keeping in the closest shelter, so that it may be within a very short distance of an eager naturalist without his being able to see it,—the olive-colour, streaked with dark brown, of its upper plumage helping to make it invisible. The nest is very artfully concealed in the thickest herbage. The foreign forms of Aquatic Warblers are far too numerous to be here mentioned.

In the scheme already mentioned, a Subfamily Drymcecinx, with 15 genera and nearly 200 species, is recognized. That such a natural group may exist is quite likely, but about its composition and limits much doubt cannot fail to be entertained. If its existence be acknowledged, the remarkable genera Orlhotomus with about 12 and Cisticola with some 30 species may be fairly admitted as belonging to it. The former includes the Tailor-birds of the Indian region of which all have heard or read, for their habit of sewing together the leaves of plants so as to form a cone in which to build their nests has often been described and the fabric figured. Jerdon (B. India, ii. p. 166) writes of the common Indian Tailor-bird, 0. longieauda, that it "makes its nest of cotton, wool, and various other soft materials," and "draws together one leaf or more, gene-rally two leaves, on each side of the nest, and stitches them together with cotton, either woven by itself, or cotton thread picked up; and, after passing the thread through the leaf, it makes a knot at the end to fix it." Oisticola, of which one species inhabits the south of Europe, follows the same trade on stems of grass, confining them by stitches above the nest, which assumes a globular form.

In the same group Drymcecinw is placed by some authors the Australian genus Malurus, to which belong the birds known as "Superb Warblers," and they are not inaptly so named, since in beauty they surpass any others of their presumed allies. Part of the plumage of the cocks in breeding-dress is generally some shade of intense blue, and is so glossy as to resemble enamel, while black, white, chestnut, or scarlet, as well as green and lilac, are also present in one species or another, so as to heighten the effect. But, as already stated, there are systematists who would raise this genus, which contains some 15 species, to the rank of a distinct Family, though on what grounds it is hard to say.

Of the other Subfamilies, Saxicolinm, Sylviinx, and Phylloscopinx, will be conveniently treated under WHEATEAR, WHITETHROAT, and [Willow-] WREN (qq.v.), while the Rulicillinm have been already mentioned under NIGHTINGALE, REDBREAST, and REDSTART, and the AccenlorinsB under [Hedge-] SPARROW.

The birds known as " American Warblers," forming what has now for a long wdiile been almost universally recognized as a distinct Family, Mniotiltidx, remain for consideration. They possess but nine instead of ten primaries, and are peculiar to the New World. More than 130 species have been described, and these have been .grouped in 20 genera or more, of which members of all but three are at least summer-visitants to North America. As a whole they are much more brightly coloured than the Sylviidx (Malurus, "if it belongs to them, always excepted); for, though the particnlnr genus Mnintilta (from which, as the fortune of nomenclature will have it, the Family takes its right name) is one of the most abnormal—its colours being plain black and white, and its habits rather resembling those of a TREE-CREEPER (q.v.)—in other groups chestnut, bluish-grey, and green appear, the last varying from an olive to a saffron tint, and in some groups the yellow predominates to an extent that has gained for its wearers, belonging to the genus Dendreeca, the name of "Golden" Warblers. In the genus Seto-phaga, the members of which deserve to be called " Fly-catching" Warblers, the plumage of the males at least presents yellow, orange, scarlet, or crimson. Dr Coues (Key N.-Am. Birds, ed. 2, p. 288), following on the whole the arrangement of Baird, Brewer, and Ridgway (N.-Am. Birds, i. p. 178), separates the whole Family (for which he arbitrarily retains the name Sylvicolidx) into three Sub-families, Sxjlvicolinse ( = Mniotiltinx), Icteriinx, and Setophaginx, grouping the genera Mniotilta.Parula, and Peucedromus as " Creep-ing Warblers"; Geothlypis, Oporornis, and Siurus as " Ground -Warblers"; Protonotaria, Helminthotherus, and HelmintlwpMla as " Worm-eating Warblers "; Setophaga, Cardellina, and Myiodioctes as "Fly catching Warblers"; Icteria, which perhaps may not belong to' the Family, standing alone; and Dendrmca as '' Wood-Warblers. "

The Mniotiltidx contain forms exhibiting quite as many diverse modes of life as do the Sylviidse. Some are exclusively aquatic in their predilections, others affect dry soils, brushwood, forests, and so on. Almost all the genera are essentially migratory, but a large proportion of the species of Dendreeca, Setophaga, and especially Basileuierus, seem never to leave their Neotropical home; while the genera Leucopeza, Tcrctristis, and Microligia, comprising in all but 5 species, are peculiar to the Antilles. The rest are for the most part natives of North America, where a few attain a very high latitude, penetrating in summer even beyond the Arctic Circle, and thence migrate southward at the end of summer or in the fall of the year, some reaching Peru and Brazil, but a few, as, for instance, Parula pitiayumi and Geothlypis relata seem to be resident in the country last named.

To return, in conclusion, to the Sylviidx, or true
Warblers, it is to be hoped that before long some com-
petent ornithologist will take on himself the task, necessary
if toilsome and perhaps ungrateful, of revising the work
that has lately been done upon them and upon tht
Turdidx, and, setting aside all preconceived notions
except that of aiming at the truth, without prejudice fix
the limits of the two Families, if Families they be, and at
the same time adjust the relations of the hitherto very
indefinite group Timeliidx. (A. >r.)


Footnotes

For this reference, not before precisely given, the writer is indebted to the Rev. G. M'Arthur.
Cf. Mr Sharpe's meritorious efforts, Cat. B. Brit. Museum, vols, vi. and vii.

2 These are exotic birds, having no recognized English name. Those of "Babblers," "Bush-Babblers," and "Babbling-Thrushes" have been applied to them by some writers, who consider them to be sufficiently characterized by their short, rounded, and incurved wings.

By some writers the Family is called Sylvicolidx, a practice which contravenes the ordinary usage of nomenclaturists, since the name Sylvicola in ornithology is preoccupied by its employment in con-chology.
Seven species have been recorded as wandering to Greenland, and one, Dendreeca virens, is said to have occurred in Europe (Nau-mannia, 1858, p. 425).