Who would believe that this small firebrand, half glowing, half charred, whirling about through the trees, as if blown by the wind, is a cousin of the sombre oven-bird that walks so daintily and leisurely over the ground? The redstart keeps perpetually in motion that he may seize gnats and other gauzy winged mouthfuls in mid-air--not as the flycatchers do, by waiting on a fence rail or limb of a tree for a dinner to fly past, then dashing out and seizing it, but by flitting about constantly in search of insect prey. The bristles at the base of his bill prevent many an insect from getting past it. He rests on the trees only long enough to snatch a morsel, then away he goes again. No wonder the Spaniards call all the gaily coloured, tropical wood warblers "Mariposas"--butterflies. {67} CHAPTER V THE VIREOS: ANOTHER STRICTLY AMERICAN FAMILY Red-Eyed Vireo White-Eyed Vireo Yellow-Throated Vireo Warbling Vireo {68} {69} THE VIREOS You know that if the birds should suddenly perish, there wouldn't be a leaf, a blade of grass, or any green thing left upon the earth within a few years--it would be uninhabitable. When Dame Nature, the most thorough of housekeepers, gave to the birds the task of restraining insects within bounds so that man and beast could live, she gave the care of foliage to the vireos. It is true that most of the warblers, and a few other birds too, hunt for their food among the leaves, but with nothing like the vireo's painstaking care and thoroughness. The nervous, restless warblers flit from twig to twig without half exploring the foliage; whereas the deliberate, methodical vireos search leisurely above and below it, cocking their little heads so as to look up at the under side of the leaf above them and to peck off the destroyers hidden there--bugs of many kinds and countless little worms, caterpillars, weevils, inchworms, May beetles, and leaf-eating beetles. Singing as they go, no birds more successfully combine work and play. Because they spend their lives among the foliage, the vireos are protectively coloured; with {70} soft grayish or olive green on their backs, wings, and tail, whitish or yellow below. Some people call them greenlets. They are all a little smaller than sparrows. More inconspicuous birds it would be hard to find or more abundant, although so commonly overlooked except by people on the look-out for them. Where the new growth of foliage at the ends of the branches is young and tender, many insects prefer to lay their eggs that their babies may have the most dainty fare as soon as they are hatched. They do not reckon upon the vireos' visits.