- Nectarinia. Illiger. Cuvier. Cæreba Brisson. Temminck. Certhia. Motacilla Linn.
- Rostrum longius, gracile, acutum, sub-arcuatum, basi crassâ, latâ, trigonâ, lateribus compressis, mandibulâ superiore apicem juxta leviter emarginatâ. Nares basales, ovatæ, breves, membranâ nudâ, in medio ovatè fissâ tectæ. Lingua longa, bifida, apice fibroso, haud extensibilis. Remigum pennæ primæ tres vix pares. Cauda mediocris, emarginata, rectricibus 12, sub-paribus.
- Bill slender, acute, slightly curved, of variable length, base thick, broad, trigonal, the sides compressed; upper mandible near the tip slightly notched; nostrils basal, oval, short, covered by a naked membrane, in the middle of which is an oval aperture; tongue long, bifid, not extensible, the tip fibrous; the three first quills of nearly equal length, and longer than the rest; tail moderate, emarginate, of 12 nearly equal feathers.
- Generic Types, Div. 1. Certhia cyanea, cayana. Div. 2. Certhia spiza, &c. Linn.
- N. (mas.) cyanea; jugulo, dorso, caudâ alisque nigris, remigibus margine cyaneo ornatis. (Fem.) Viridis; capite, genis scapulisque cærulescentibus; jugulo cano.
- (Male.) Changeable blue; throat, back, tail, and wings black; the quills edged with blue. Female green; head, cheeks, and scapulars bluish; throat grey.
- Motacilla cayana. Linn. Gmelin, 1. 990.
- Sylvia cayana. Lath. In. Orn. 2. 545. Gen. Zool. 10. 655.
- Pepit bleu de Cayenne? Brisson, Ois. vol. 3. pl. 28. 1.
- Cayenne Warbler. Lath. Syn. 4. 502. Gen. Zool. 10. 655.
- Sylvia Cayenensis cærulea. Brisson, Orn. 1. p. 455.
- Motacilla cyanocephala. Gmelin, 1. 990.
- Sylvia cyanocephala. Lath. In. Orn. 2. 546. Gen. Zool. 10. 684.
- Sylvia viridis. Brisson, Orn. 1. p. 455.
- Le Pepit verd. Brisson, Ois. 3. pl. 28. f. 4.
- Blue-headed Warbler. Lath. Syn. 4. p. 503.
- Blue-headed Creeper? Lath. Syn. 2. p. 727.
Few birds require more illustration than this very beautiful though common species; described by most ornithological writers, but hitherto so little understood, that the two sexes stand as distinct species in a family of birds to which they have, in reality, no natural affinity. According to the Linnæan system it should have been rather placed with the Creepers than the Warblers; an error which has been continued by every subsequent writer, even by Professor Temminck, whose skilful and accurate perception of natural affinities is, in general, so remarkably correct.
That these two birds, however dissimilar in colour, are the sexes only of one species, repeated dissections in their native country have put beyond all doubt; and that it is a genuine Nectarinia (or Cæreba of Temminck) will appear from submitting it to a rigorous comparison with the characters the Professor himself has laid down for that genus.
Its habits are no less perfectly the same as the rest of the Nectariniæ; it is one of the commonest birds of Brazil, and appears spread over the whole extent of that country. It frequents the same trees as the Humming-birds, hopping from flower to flower, and extracting the nectar from each; but this is not done on the wing, because its formation is obviously different from the Humming-birds, which, on the contrary, poise themselves in the air during feeding. The shortness of the bill has evidently given rise to this bird being placed with the Warblers; but this organ is not shorter in proportion than it is in Nectarinia spiza, (Certhia spiza of Latham).
I am unacquainted with the other varieties of this species mentioned by authors. Of the bird here described, I have never seen any variety, either in Brazil or in our museums. The young males, as usual before moulting, have the colours of the female; one of them, in an intermediate state, is in my possession. As both the figures are of the size of life, and accurately coloured, a fuller description is unnecessary. The rich sky-blue of the male, in some lights, becomes greenish, and in others dark blue. The bill, like that of all the genuine Nectariniæ, is slightly notched a little way from the tip, and the base is much broader than high.