Such is the silence of the bush that the silken rustle of the butterflies becomes audible and the distinctive flight of birds is recognised--not alone such exaggerated differences as the whirr of quail, the bustle of scrub fowl, and the whistle and clacking of nutmeg pigeons, but the delicate and tender characteristics of the wing notes of the meeker kinds of doves and the honey-eaters, and also the calculated flutterings of the fly-catchers. In the whistling swoop of the grey goshawk there is a note of ominous blood-thirstiness, silent though the destroyer has sat awaiting the moment for swift and decisive action. Seldom, even on the stillest evening, may the presence of the night-jar be detected, except by its coarse call, while the sprightly little sun-bird flits hither and thither, prodigal of its vivid colours and joying with machine-like whirring. The sun-bird exemplifies the brightness of the day. All its activities are bold and conspicuous. Aptly named, it has nothing to hide, no deeds which will not withstand the scrutiny of the vividest rays. To work out its destiny the night-jar depends on secret doings and on flight soft as a falling leaf. It is a bird of the twilight and night. Startled from brooding over its eggs or yet dependent chicks, it is ghost-like in its flittings and disappearances. In broad daylight it moves from its resting-place as a leaf blown by an erratic and sudden puff, and vanishes as it touches the sheltering bosom of Mother Earth. Mark the spot of its vanishment and approach never so cautiously, and you see naught. Peer about and from your very feet that which had been deemed to be a shred of bark rises and is wafted away again by a phantom zephyr. The chick which the parent bird has hidden remains a puzzle. It moves not, it may not blink. Its crafty parent has so nibbled and frayed the edges of the decaying brown leaves among which it nestles that it has become absorbed in the scene. There is nothing to distinguish between the leaf-like feathers and the feather-like leaves. The instinct of the bird has blotted itself out. It is there, but invisible, and to be discovered only by the critical inspection of every inch of its environment. You have found it; but not for minutes after its instinct has warned it to possess its soul calmly and not to be afraid. So firm is its purpose that if inadvertently you put your foot on its tender body it would not move or utter cry. All its faculties are concentrated on impassiveness, and thus does Nature guard its weakest and most helpless offspring. While you ponder on the wonderful faith of the tiny creature which suffers handling without resistance, the shred of bark, driven by the imperceptible zephyr, falls a few yards away, and in an agony of anxiety utters an imploring purr, or was it an imprecation? That half purr, half hiss has been the only sound of the episode. It is a warning to be gone and leave Nature to her secrets and silences.