Page:Natural History, Birds.djvu/225

212 species, the plumage of which is radiant with emerald-green, purple, and bronzed reflections.

Of this extensive genus the distinctive characteristics are the following: the beak is broad and rather depressed at the base, with the culmen curved, and the sides compressed towards the tip, which is entire and acute; the nostrils are placed on each side of the base, in a short, broad, membranous groove, with the opening round and exposed; the wings comparatively long and pointed, the third quill longest; the tail long, usually graduated, the outmost feather on each side much shorter than the rest; the tarsi are very short, feathered below the heel, the exposed part covered with broad scales.

The species are confined to the eastern hemisphere, over the warmer parts of which they are extensively and numerously distributed: two only occur in Europe, the one as a constant, the other as an occasional summer migrant from the sunny regions of Africa: most of the species, indeed, are more or less migratory. Their habits are recluse and solitary, frequenting woods, or at least places where thick trees abound; and they are wary and jealous of the approach of man. They do not fly with much apparent power, but content themselves, in common, with gliding on steady wing from one tree to another. At the season of migration, of course, they must be able to sustain a flight protracted for many leagues. The food of these birds consists largely of caterpillars, especially the thick hairy larvæ of the greater