The foregoing remarks apply to the Dendrocolap-tidae throughout the temperate countries of South America--the birds inhabiting extensive grassy plains and marshes, and districts with a scanty or scattered tree and bush vegetation. In the forest areas of the hotter regions it is different; there the birds form large gatherings or "wandering bands," composed of all the different species found in each district, associated with birds of other families--wood-peckers, tyrant-birds, bush shrikes, and many others. These miscellaneous gatherings are not of rare occurrence, but out of the breeding season are formed daily, the birds beginning to assemble at about nine or ten o'clock in the morning, their number increasing through the day until it reaches its maximum between two and four o'clock in the afternoon, after which it begins to diminish, each bird going off to its customary shelter or dwelling-place. Mr. Bates, who first described these wandering bands, says that he could always find the particular band belonging to a district any day he wished, for when he failed to meet with it in one part of the forest he would try other paths, until he eventually found it. The great Amazonian forests, he tells us, appear strangely silent and devoid of bird life, and it is possible to ramble about for whole days without seeing or hearing birds. But now and then the surrounding trees and bushes appear suddenly swarming with them. "The bustling crowd loses no time, and, always moving in concert, each bird is occupied on its own account in searching bark, or leaf, or twig. In a few moments the host is gone, and the forest path remains deserted and silent as before." Stolzmann, who observed them in Peru, says that the sound caused by the busy crowd searching through the foliage, and the falling of dead leaves and twigs, resembles that produced by a shower of rain. The Indians of the Amazons, Mr. Bates writes, have a curious belief to explain these bird armies; they say that the Papa-uira, supposed to be a small grey bird, fascinates all the others, and leads them on a weary perpetual dance through the forest. It seems very wonderful that birds, at other times solitary, should thus combine daily in large numbers, including in their bands scores of widely different species, and in size ranging from those no larger than a wren to others as big as a magpie. It is certainly very advantageous to them. As Belt remarks, they play into each other's hands; for while the larger creepers explore the trunks of big trees, others run over the branches and cling to the lesser twigs, so that every tree in their route, from its roots to the topmost foliage, is thoroughly examined, and every spider and caterpillar taken, while the winged insects, driven from their lurking-places, are seized where they settle, or caught flying by the tyrant birds.