Sired by a sunbeam, born of a flower, gaiety its badge, might be said in fable of the sunbird, as in temperament and tint it parades its right to such parentage. Sprightly, sudden in many shifts, not disposed to be over-trustful — yet for its diminutiveness, gay colours, habits and inconsequence it is likeable if not lovable, a gem to be thankful for and to admire. An ornament in the garden, a shy, fragile habitant of the bush, artificial rather than a work of unassisted nature, it seems to understand its frailty and to take, perhaps, unnecessary precautions against the assaults of enemies, especially during the nesting-season.
Occasionally the nest is built under the verandah. A pair, bolder than the others, selected the boatshed, where both building and incubation were subject to many interruptions and yet successfully concluded. Generally independence is preferred, and in forest or on the fringe of the jungle or on a branch overhanging the beach the nest will be found; and always it is so artfully draped as rarely to be detected, apart from the presence of the builders. An example may be described.
As it passes from maturity to decay the spathe of the commonest of the pandanus palms becomes brown and mildewed, and, caught by the prickle-edged leaves in tufts and shreds, the flowers may hang loosely in the air. One such dangling plume became a source of trivial annoyance, for it was suspended over a frequently traversed path just high enough to flap the face of the heedless passerby. Other leaves of the palm were similarly decorated all showing the processes of change and decay more or less conspicuously. In course of time that which had occasioned many an unconscious swerve littered the path, still clinging to the sword-shaped leaf, and in the midst was an unsuspected nest in which a brood had been reared.
Different in its concealment was a nest woven on the frayed end of a strip of bark still attached to the trunk of a massive tea-tree. Threads of the bark were interwoven with the body of the nest, and a graduated strand was the customary pendant. But for a chance visit from the male bird, with his yellow chest and blue bib, the gently swaying nest would never have been noticed.
Do such birds consciously conceal their nests? Are not their only enemies snakes, which depend on the sense of smell, not of sight, and are accordingly not subject to illusions which the elaborate deceptions seem designed to create? As far as outside show goes, the completed nest is a tattered, tapering remnant of inanimate nature, with an entrance so secret and downcast that the parent bird seems to enter from below, while within it is cosy and softly lined, befitting the occupation of chicks with an inborn leaning towards comfort and safety.
Though the nest may have no delusive effect on a marauding snake, its lightness, insecure situation, and the obscurity of the entrance may in combination afford a fair measure of protection. So, with or without design, the frivolous sunbird outwits the reptile which was wont to be emblematic of subtlety and craft.
Nests under the surveillance of human beings are simpler exteriorly than those of the bush, no trouble being taken to adjust them in appearance to their surroundings; and not a single local instance can be cited of an attempt to blur such nests other than by a trivial tail-piece. Those who scoff at the suggestion that birds are capable of apprehending the object to be accomplished may be able to explain why the sunbirds do not blindly obey the laws of instinct and efface nests under artificial cover with oddments, making them as usual, things of shreds and patches. Whether they were aware of the needlessness of concealment, or whether in the lack of suitable material they abandoned the habit, are questions for others to discuss. Here is one who, like Rosa Dartle, “wants to be put right, if wrong” in believing that birds and other creatures of less mental equipment than ourselves have, at least, the faculty of varying the habitual performance of an intelligent action in accordance with necessities and circumstances.
The shrill, small voice of the sunbird is almost indistinguishable from the stridulation of one of the leaf insects, which makes its amorous noises in the evening as well as during the sunny hours. Frequently both sounds are heard in confusing blend. Many times have the red hibiscus bushes been searched for the fitful, flittering sunbird in vain, while the red-eyed insect which hides under the mimicry of a pair of green leaves has proclaimed its passion with impatient fervour.
The insects were plentiful, but the birds had been rare during a considerable interval, the cyclone of March, 1918, having destroyed so many that for a time it was feared they must be counted among the losses due to one devastating night. During this year (1921) the birds have shown signs of recovering the lost ground, so far as numbers are concerned. A family of six on the crown of an umbrella-tree gave welcome proof of increase; and, though without appeal to the sensual ear, were not the hasty twitters of the sprites sounds of triumph over the storm which, having ravaged beaches, scarred hills, maimed every food-providing plant and driven strong-winged birds across the sea, had merely checked for a season the well-being of the weak?
Science does not recognize distinct association between the sunbird and the humming-bird of America, yet in habits and in certain poses resemblance may be traced. Both live on minute flower-frequenting insects, and refresh themselves with nectar. Both poise over the flowers they visit, though the accomplishments of the sunbird in the feat are less assured, less frequently displayed, and of less duration than those of the “miniature miracle of nature which delights to revel among the honeysuckle bowers.” The ancient Mexicans believed that the humming-bird suspended its animation and its body during the cold season of the year; that it drove its long bill into the bark of a tree and thus spent the rigorous winter, waking at the coming of spring, to feast on spiders and quaff honey. True to their familiar name, our sunbirds are silent during the rains of the wet season; but on the first gleam of sunshine they bustle among the flowers, performing pretty feats of agility and joining in a musical competition with their neighbours of the leaf.
Boldly located, but so shaded that it blends with the scene, the nest of the North Queensland sunbird is artless compared with those of two relatives native to North Borneo, in which concealment is exemplified on altogether different principles. Three singular nests are referred to in A NATURALIST IN BORNEO, by the late Robert W. C. Shelford. A brief quotation may be pardoned on the plea of the value of comparisions. One is described as a hemispherical cup of interwoven fibres covered with skeleton leaves, slung by silken threads to the under surface of a large leaf. The suspensory threads (obtained from spiders’ webs) “are passed through holes made in the leaf by the bird’s bill, and the ends are twisted up into knots to prevent slipping.” This one is said to be not only fairly secure from observation but well protected from snakes. Another, composed of skeleton leaves and fibres and bast, is placed between two growing leaves pegged together with bits of stick. A third bears some resemblance of that of the North Queensland species, being a pear-shaped structure of bark fibres and cocoons of silk-weaving caterpillars, with entrance at the side under an overhanging eave. It dangles from the end of a bough.
In the selection of sites for nests, in style, material and manipulation, sunbirds must be credited with exceptional skill. These are external matters from which each species benefits in accordance with its lights. In proof of regard for general welfare — for the preservation of the type — it may be pointed out that they adhere to one principle. Though the breasts of males are vivid, the backs of all conform to the tints of vegetation, so that during moments of stillness the gift of invisibility is theirs. They do homage to the sun, glory in its patronage, mimic its rays as they gleam and flicker among reflecting leaves, and while at rest simulate shadowed ones.
But what is this? One of the sweet creatures, discovering a tiny spider lurking in a corner of the window, flutters against the incomprehensible glass, taps it with pointed bill, and, baffled, flits off, tittering with vexation. Better its company in the sunshine than these shady studies of its architectural skill.
Last updated Monday, December 22, 2014 at 10:47