Bird Identification – 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 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.
Toward the end of April or the first of May, these tireless gleaners return to us from Central and South America where they have spent the winter, which of course you know, is no winter on the other side of the equator, but a continuation of summer for them. Competition for food being more fierce in the tropics than it is here, millions of birds besides the warblers and vireos travel from beyond the Isthmus of Panama to the United States and back again every year in order that they may live in perpetual summer with an abundance of food. If any child thinks that birds are mere creatures of pleasure, who sing to pass the time away, he doesn’t begin to understand how hard they must work for a living. They cannot limit their labours to an eight-hour day. However, they keep cheerful through at least sixteen busy hours.