How remarkable it is that development and even beauty should be bestowed upon the under tail-coverts of a bird! yet this is often found to be the case: the Marabou Stork may be cited as an instance in point among the larger birds, and the genera Eriocnemis, Erythronota, &c. among the Trochilidæ. In no group, however, is this feature so conspicuously marked as in the members of the succeeding genus Chalybura; there it is carried to its maximum, and is rendered so much the more apparent from the striking contrast of the snow-white-plumed under tail-coverts with the dark or black colouring of the tail-feathers. These birds form a very natural section of the Trochilide. Venezuela, New Granada, and Panama may be regarded as their head quarters,—two of the species, C. Buffoni and C. cæruleogaster, being frequently sent in collections from Bogota.
Although the sexes of this genus of birds are very differently coloured, the females have the plumed under tail-coverts as well as the males.
Chalybura Burffoni
Habitat: Venezuela and New Granada
Plate 89
Hypuroptila Buffoni
Buffon’s Plumeleteer
Chalybura urochrysia (Gould)
Habitat: Panama
Plate 90
Hypuroptila urochriysia
Golden-tailed Plumeleteer
Chalybura cæruleogastra (Gould)
Habitat: New Granada.
Plate 91
Hypuroptila cæruleogaster
Blue-breasted Plumeleteer
Chalybura? Isauræ (Gould)
Habitat: The Bocca del Toro in Costa Rica
No illustrations
Head, all the upper surface, wing-coverts, flanks, and abdomen coppery bronze, inclining to purple on the lower part of the back and upper tail-coverts; wings purplish-brown; tail very dark bronze, inclining to purple; throat and breast grass-green; under tail-coverts white; upper mandible black; under mandible fleshy, with a black tip; tarsi yellow or flesh-colour.
Total length 4\(\frac{5}{8}\) inches; bill 1\(\frac{1}{16}\); wing 2\(\frac{5}{8}\); tail 1\(\frac{3}{3}\); tarsi \(\frac{1}{4}\).
The specimen from which the above description was taken is somewhat immature; it is, however, sufficiently advanced to show that it would have, when adult, a fine green breast; but whether the green colour would extend over the abdomen, I am unable to say. It is nearly equal in size to the C. urochrysia, C. Buffoni, and C. cæruleogastra; but it has a shorter wing and a more rounded tail than either of those species, and the under tail-coverts, though white, are less plume-like in form. It is just possible that it may be necessary to separate this bird into a new genus when we see it in its fully adult state; but it appears at present to be most nearly allied to the members of the genus in which I have provisionally placed it. I received this bird from M. Edouard Verreaux, of Paris, many years ago, and I have never seen another.
The name of Isauræ was suggested to me by my late highly valued friend the Prince Charles Lucien Bonaparte, who wished thus to convey a compliment to Madame la Baronne de Lafresnaye, the niece of Montbeillard, the able coadjutor of the celebrated Buffon.
Featuring all 422 illustrated species from John Gould’s A Monograph of the Trochilidæ, or Family of Humming-Birds arranged by color.
Humming-Birds
