SUN-BIRD, a name more or less in use for many years, 1 and now generally accepted as that of a group of over 100 species of small birds, but when or by whom it was first applied is uncertain. Those known to the older naturalists were for a long while referred to the genus Certhia (TREE-CREEPER, q.v.) or some other group, but they are now fully recognized as forming a valid Passerine family Nectariniidae, from the name Nectar inia invented in 1881 by Illiger. They inhabit the Ethiopian, Indian, and Australian regions, 2 and, with some notable exceptions, the species mostly have but a limited range. They are considered to have their nearest allies in the Meliphagidae (see HONEY-EATER) and the members of the genus Zosterops; but their relations to the last require further investigation. Some of them are called " humming-birds " by Anglo-Indians and colonists, but with that group, which, as before indicated (see HUMMING-BIRD), belongs to the Picariae, the sun-birds, being true Passeres, have nothing to do. Though part of the plumage in many sun-birds gleams with metallic lustre, they owe much of their beauty to feathers which are not lustrous, though almost as vivid, 1 and the most wonderful combination of the brightest colours scarlet, purple, blue, green and yellow is often seen in one and the same bird. One group, however, is dull in hue, and but for the presence in some of its members of yellow or flame-coloured precostal tufts, which are very characteristic of the family, might at first sight be thought not to belong here. Graceful in form and active in motion, sun-birds flit from flower to flower, feeding on small insects which are attracted by the nectar and on the nectar itself; but this is usually done while perched and rarely on the wing as is the habit of humming-birds. The extensible tongue, though practically serving the same end in both groups, is essentially different in its quasi-tubular structure, and there is also considerable difference between this organ in the Nectariniidae and the Meliphagidae. 2 The nests of the sun-birds, domed with a penthouse porch, and pensile from the end of a bough or leaf, are very neatly built. The eggs are generally three in number, of a dull white covered with confluent specks of greenish grey.
The Nectariniidae form the subject of a sumptuous Monograph by G. E. Shelley (410, London, 1876-1880), in the coloured plates of which full justice is done to the varied beauties which these gloriously arrayed little beings display, while almost every available source of information has been consulted and the results embodied. This author divides the family into three sub-families: Neodrepaninae, consisting of a single genus and species peculiar to Madagascar; Nectariniinae, containing 9 genera, one of which, Cinnyns, has more than half the number of species in the whole group ; and Arachnotherinae (sometimes known as "spider-hunters"), with 2 genera including 1 1 species all large in size and plain in hue. To these he also adds the genus Promerops, 3 composed of 2 species of South African birds, of very different appearance, whose affinity to the rest can as yet hardly be taken as proved. According to E. L. Layard, the habits of the Cape Promerops, its mode of modification, and the character of its eggs are verv unlike those of the ordinary Nectariniidae. In the British Museum Catalogue of Birds (ix. 1-126 and 291) H. J. Gadow has more recently treated of this family, reducing the number of both genera and species, though adding a new genus discovered since the publication of Shelley's work.
 Certainly since 1826 (cf. Stephens, Gen. Zoology, vol. xiv. pt. I, p. 292). W. Swainson (Nat. Hist., and Classif. Birds, i. 145) says they are " so called by the natives of Asia in allusion to their splendid and shining plumage," but gives no hint as to the nation or language wherein the name originated. By the French they have been much longer known as " Spuimangas," from the Madagascar name of one of the species given in 1658 by Flacourt as Soumangha.
 One species occurs in Baluchistan, which is perhaps outside of the Indian region, but the fact of its being found _there may be a reason for including that country within the region, just as the presence of another species in the Jordan valley induces zoographers to regard the Ghor as an outlier of the Ethiopian region.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)