Page:Popular Science Monthly Volume 33.djvu/85

Rh By virtue of being a thrush, our robin enjoys a very extensive range of country for his habitat. From the Atlantic to the Pacific, across the continent, from the shores of the Arctic Ocean to Mexico and Central America, he is found abundantly, breeding throughout the forest limits of this wide area, and building the same nest of dried grass, roots, and plastered mud about every homestead in the land. Although a bird of the woodland, like all the thrushes, he yet prefers the garden and the orchard—even the trees that stand in the midst of the bustling city hold his nest. Insectivorous by nature, but varying his diet largely with the small, wild berries of the woods, the robin has become, since man's invasion, a lover of fruit, keeping pace with man in the cultivation of his taste. The excellence of his taste can not be denied. He takes the biggest cherries of the most approved varieties, and the luscious straw-berries are his delight. Yet for all the fruit he eats he repays the horticulturist double by devouring threefold more of insect-life that would ultimately cover and destroy the trees, leaf, root, and branch. Fortunate it is that we have recognized his valuable service, and protected him by legislation.

The true thrushes—and the robin may be taken as a type—present some very interesting features in their development, characters, and geographical distribution, a study of which throws light not only upon the history of the birds themselves, but also upon several widely different subjects.

The thrushes belong to the most highly organized group of birds—the Passeres—and are farthest removed in structure from the early reptiloid forms. They possess the most complete vocal apparatus—a syrinx—situated at the lower end of the windpipe, with five intrinsic pairs of muscles. The wing has undergone a reduction in the number of its primaries or quill-feathers growing from the long finger, there being ten of these, the first one short and abortive, so that the thrushes may be looked upon as still advancing toward the highest type of wing-structure, that of nine primaries. In conjunction with this, the foot or leg is "booted"—i. e., covered by an unbroken plate of hard, leathery skin, not reticulated and scaled, as in other forms. A decided change has also taken place in the "molt," or shedding of