Fig. 89.–Humming-bird. Eulampis jugularus. × ⅔.
Darwin[[248]] writes of Patagona gigas: "Like others of the genus, it moves from place to place, with a rapidity which may be compared to that of Syrphus among diptera and Sphinx [especially the Humming-bird Sphinx (Macroglossa stellatarum)] among moths, but whilst hovering over a flower, it flaps its wings with a very slow and powerful movement, totally different from that vibratory one, common to most of the species, which produces the humming noise." This slower movement has been observed also in Pterophanes temmincki, and no doubt in other large forms, of which the aerial course is perhaps more zigzag and jerky than elsewhere. Certain species habitually sit with puffed out plumage and somewhat elevated bills; others soar, or skim the surface of water like Bats; the tail-feathers, moreover, are often moved sideways or twisted during flight, especially when they are elongated or spatulate; and Loddigesia constantly extends them perpendicularly to the body, if not further forward, though the racquet-tips may at other times be almost in contact.
The food consists almost entirely of insects, while the alimentary canal shews but little trace of honey, which the birds nevertheless seem to enjoy, when swallowed with the creatures which it allures; and as these appear on the lips of flowers chiefly after wet, or in the morning and evening, their feathered foes are naturally then most active. Cacti, alstroemeriae, orchids, and composites seem particularly attractive, and tubular blossoms to the long-billed species especially. Those with shorter beaks, being unable to penetrate the deepest tubes, are said to pierce the hinder portions, while it is asserted that those with extremely curved mandibles even make use of a twofold process, first inserting the tips, and then raising themselves slightly so as to penetrate the recesses. Rhamphodon, Phaëthornis, Eutoxeres, and Chlorostilbon examine the crevices of trees and walls for spiders, which they habitually eat; while the "Hermits," balanced in the air, pass the bill carefully though quickly over the lower surface of leaves in search of insect-diet. Oreotrochilus pichincha has been observed clinging to rocks and feeding upon the ground; Aithurus, Petasophora, Pygmornis, Lampornis, Patagona and other species, take up posts on dead branches or twigs, thence darting upon their prey in Fly-catcher-like style. Gould once managed to reach the shores of England with two examples, kept alive on sweetened water and yolk of egg.
The males are extraordinarily pugnacious, and one will furiously set upon another who interferes in the least with his comfort, the pair circling around with reiterated, high-pitched notes, attacking and withdrawing in turn, almost heedless of a fall or collision; finally, beak grasps beak, and the struggle grows more intense, until the defeated combatant retreats to some friendly tree, only to renew the fight with vigour unimpaired should his defiant note exasperate his rival beyond control. Or again, should a prowling hawk, an inoffensive heron or thrush, or even a human being, pass perilously near a nest, the cock will make a determined onslaught, often with complete success; the hen following his example, if she feels called upon to protect her charge. These tiny creatures seem absolutely fearless, and frequently feed at once from the hand when caught.
The twittering voice is variously described as a chirp, a squeak, a querulous warble, a whistle, a loud clear piping cry, or a shrill screech, while the absence of proper song-muscles makes it difficult to credit Gosse's statement that Mellisuga minima utters a weak, sweet warble, lasting for ten minutes.[[249]]
The nest is usually a moderately deep, round or oval cup-like structure, which may be no larger than a walnut-shell; this is formed of the cottony down of plants, moss, wool, or like materials, felted into an extremely light and spongy mass, and often decorated externally with lichens, cobwebs, shreds of bark, or even feathers and dry leaves. It is placed in a small fork, saddled upon a bough, hung from creepers, laced among branchlets, or exceptionally fastened to thatch. In Rhamphodon, Phaëthornis, Cephalolepis, Heliothrix, and possibly elsewhere, a fabric of very delicate twigs, fibres, and bark is attached to the lower part of a palm or similar leaf, several rings of supporting fibre encircling the portion near the stalk, and spiders' webs or silky threads aiding to sustain the sides of the structure, which in depth and make recalls that of the Reed-Warbler. Oreotrochilus forms a peculiar "hammock" of moss, grass, and so forth, attached by like contrivances to rocks; or at times suspends a mass of wool, hair, moss, and feathers, as large as a child's head, with a small depression above for the eggs, from pendent roots, tendrils, or creepers. This is said to be weighted on either side, if necessary, with small stones or morsels of earth, and is repaired for use in successive years. Humming-birds never lay more than two eggs, and sometimes only one; these are plain dull white, and similarly shaped at both ends. The young are hatched blind and naked, and are then about the size of humble bees: but they leave the nest comparatively soon, and are precocious as regards flight. The duration of incubation, which is apparently not shared by the male, is variously stated at ten, twelve, or even more days, and two broods are said to be reared in a season; the first point is clearly doubtful; but, considering the extent of the season fit for nidification, the latter is not improbable. The parents have been known to add to a nest, as the young outgrew it. The cock courts the hen most assiduously, circling around her with dilated throat and swelling plumage, and searching for food to offer, while he carefully watches over her when sitting. Humming-birds have been often said to be killed with water in place of lead, but in truth diminutive pellets of the latter are used, as an alternative to the blow-pipe with its clay ball, or to bird-lime. Immense quantities are exported for decorative purposes, and the Mexicans make pictures of the feathers.
The late Mr. Salvin, who divided the Family into groups by the serration of the beak,[[250]] recognised a hundred and twenty-seven genera with some five hundred species, while Audubon, Bates, Gosse, Gould, Mulsant, Wilson and Waterton, Count Berlepsch, Messrs. Elliot, Hartert, Ridgway, and Wallace may be mentioned among other Trochilidists. The largest form, Patagona gigas, measures nearly nine inches, Mellisuga minima and others about two and a half.
(1) Forms with distinctly serrated beaks. Heliothrix of Central and South America southward to Brazil contains three members with wedge-shaped bills and blue tufts behind the ears. The females differ little from the males in colour, but have longer tails. Augastes contains the two "Vizor-bearers" of South-East Brazil, so-called from the appearance of the head and throat; A. lumachellus is bronzy green, with a very brilliant green throat terminated by a red line, a little blue shewing between these two colours; the crown is velvety black, the pectoral band white, the tail bright bronzy-red. The female is less highly coloured and has a green head. Rhamphodon naevius of the same country, and Androdon aequatorialis of Colombia and Ecuador, have the bill strongly hooked; the latter is brownish-green above and greyish below, with a blue nape and white rump-bar.
Fig. 90.–Long-tailed Humming-bird. Aithurus polytmus. × ½.