Other curious appendages are to be met with in species of this family. One group has exceedingly long tails, three or four times the length of the body. Several Humming Birds have the outer feathers of the tail long, and though narrow for the greater part of their length, suddenly expanded at the end like a paddle or a spoon. These seem to form a group or sub-genus of their own, and are also remarkable for having the upper part of the leg (the tibia, and sometimes part of the tarsus) covered with a thick mass of white downy feathers, presenting one of the many instances of phenomena to which it appears almost impossible in the present state of our knowledge, to assign a use in the economy of the species. The wings in all Humming Birds are large, when compared with those of many other birds, and are formed for long-continued and rapid flight.
The food of the Humming Birds is now well ascertained to be principally insects. We regard the conclusion, also, as unavoidable, that the moisture contained in flowers is their drink only, and not capable alone of supporting life. The tongue appears to be the principal organ used both in capturing insects and in procuring the fluid portion of their subsistence, and is constructed in a manner peculiarly adapted to these purposes. It is long, and composed of two parallel tubes (like a double-barrelled gun), furnished with the necessary apparatus of muscles for sucking, and thus enabling the bird to reach the drops of moisture or the fluid secretions contained very frequently in the corollas of flowers, more abundant in some species than others. The tongue is flattened, and sometimes barbed towards the end, or margined with fringe-like appendages, evidently designed to be of material service in feeding on minute flies or other small and soft insects. It admits, too, of being darted outwards, like that of the woodpeckers, and in the manner thus indicated it is very probable that their food is secured.
A large space on the throat is generally the most beautiful part of the plumage of the birds of this family. Frequently, however, the top of the head and the entire under parts of the body are clothed in colors of the most surpassing brilliancy. The upper parts are usually plainer.
In the countries where these birds are most abundant, and even in others of South America, some species of Humming Birds are spread over a vast extent of territory;—other species are well known to be peculiar to quite restricted localities. Many inhabit only the warmest districts;—others are found only in mountain-valleys, thousands of feet above the level of the sea. One of the most beautiful Humming Birds, the Polytmus (Trochilus polytmus), a large species, having the plumage mainly of a most exquisite green, with the top of the head jet black, and with the tail excessively long, inhabits only the island of Jamaica, and it is quite probable that every island of the West Indies produces species which are to be found in no other. In some sections, they are exceedingly numerous. Mr. Gosse, in his valuable volume on the Birds of Jamaica, mentions having seen “no less than a hundred come successively to rifle the blossoms within the space of half as many yards in the course of a forenoon.” We have been informed of instances of the ruby-topaz Humming Bird (T. moschitus) having occurred in the island of Trinidad in even greater abundance.
In allusion to the general abundance of these birds in the countries where they abound, and as a sketch of their habits, we transcribe the following from “A Voyage up the Amazon,” from an excellent observer and agreeable writer, our friend, Mr William H. Edwards, of New York:
“Wherever a creeping vine opens its fragrant clusters, or wherever a tree-flower blooms, may these little birds be seen. In the garden, or in the woods, over the water, everywhere, they are darting about;—of all sizes, from one that might easily be mistaken for a different variety of bird, to the tiny Hermit (Trochilus rufigaster), whose body is not half the size of the bees buzzing about the same sweets. Sometimes they are seen chasing each other in sport with a rapidity of flight and intricacy of path the eye is puzzled to follow. Again circling round and round, they rise high in mid-air, then dart off like light to some distant attraction. Perched upon a little limb, they smooth their plumes and seem to delight in their dazzling hues; then starting off leisurely, they skim along, stopping capriciously to kiss the coquetting flowerets. Often, two meet in mid-air and fight furiously, their crests and the feathers on their throats all erected and blazing, and altogether pictures of the most violent rage. Several times we saw them battling with large black bees, who frequent the same flowers, and may be supposed to interfere often provokingly. Like lightning, our little heroes would come down, but the coat of shining mail would ward of their furious strokes. Again and again would they renew the attack, until their anger had expended itself by its own fury, or until the apathetic bee, once roused, had put forth powers that drove the invader from the field.”
The Mexican Humming Birds have been, until recently, but little attended to, and even at this time are by no means well known. In an interesting volume by Mr. William Bullock, a Fellow of the Linnean Society of London, “Six Months Residence and Travels in Mexico” (London, 1824), a work that contains much information on the natural history, and especially the ornithology, of that country, there is a chapter exclusively devoted to the Humming Birds. From it, we make the following extract, which may be regarded as the more interesting, as some of the species alluded to may be found hereafter in those parts of the United States contiguous to Mexico:
“In Mexico, the species of Humming Birds are numerous. Near the capital, on my arrival, scarcely one was to be seen; but in the month of May and June, numbers were found in the Botanic Garden, in the centre of the city; and, by offering a reward to the Indians, many were brought to me alive. I had nearly seventy in cages, which, with attention and care, I kept living for some weeks; and could I have devoted my whole attention to them, I have no doubt of the possibility of bringing them alive to Europe.
“It is probable the whole of them feed on insects; numbers I am certain do so, having watched them attentively in the Botanic Garden at Mexico, in pursuit of their minute prey; and in the yard of the house in which I resided at Themascaltepec, where one of them took entire possession of a pomegranate tree in blossom, on which he sat the whole day, catching the small flies that came to the flowers.
“Although, like the Robin and other birds of Europe, in a state of nature, they are extremely tenacious of any intrusion of their own species on their dominions, yet, in captivity, when several kinds have been confined together, I never observed the least inclination to quarrel, but have seen the smaller take what appeared to be unwarrantable liberties with those of five times their size and strength;—thus, when the perch has been occupied by the great blue-throated one, the diminutive Mexican Star has settled on the long beak of the former, and remained perched on it some minutes, without its offering to resist the insult.