The bird visitors to the tree arrived in one of two characteristic ways. Many came direct and swiftly, singly or in pairs, flying straight and with decision. These came from a distance, with full knowledge of the berries. They fed quietly, and when satiated flew off. The second method of arrival was wholly casual,—loose flocks drifting slowly from the neighboring jungle, sifting into the tree, and feeding for a time before passing on. When these left it was rather hastily, and in answer to the chirps and calls of the members of their flock who had not been beguiled by the berries and hence had forged steadily ahead.
These more or less well-defined flocks are very characteristic of all tropical jungles. Little assemblages of flycatchers, callistes, tanagers, antbirds, manakins, woodhewers, and woodpeckers are drawn together by some intangible but very social instinct. Day after day they unite in these fragile fraternities which drift along, gleaning from leaves, flowers, branches, trunks, or ground, each bird according to its structure and way of life. They are so held together by an intangible gregarious instinct that day after day the same heterogeneous flock may be observed, identifiable by peculiarities of one or several of its members. The only recognizable bond is vocal—a constant low calling; half unconscious, absent-minded little signals which keep the members in touch with one another, spurring on the laggards, retarding the overswift.
While I watched, there came to my tree a single species of pigeon, two hawks, and two parrots, four hummingbirds, and an equal number of toucans and woodpeckers. The remaining fifty-nine were all passerine birds, of which there were eight each of the families of flycatchers, manakins, and cotingas. Eleven were tanagers.
The greedy, noisy parrakeets were always the center of commotion, wasting more berries than they ate. The toucans, those bizarre birds of whose lives we know so little, yelped and called and bathed in the water caught in the stubs of branches, and fed to repletion. All the flycatchers forgot their usual diet and took to berrying as ardently as the tanagers themselves. Not all the birds came to feed on the berries. A wren hunted insects among the branches, and a hawk found a giant snail crawling up the trunk and devoured it. The insect-eaters of the trunk numbered nine and showed no interest in the berries. Two were woodpeckers and seven woodhewers.
These latter are a strange tropical family four hundred strong, and all the very essence of protective coloring. Their habits of life make of them wandering bits of bark, easy to detect when they are in motion, but vanishing utterly when they are quiet. Their similarity in dress is remarkable. They may be large or small, short or long-tailed, with beaks blunt, sharp, straight, curved, thick, or needle-pointed. In these characters they differ; by these points they must know one another. But their colors are almost identical. Their olives or browns invariably warm into rich foxy rufous on wings and tail, while over head and shoulders a shower of light streaks has fallen, bits of sunlight fixed in down.
Further details belong to the literature of ornithology. But the colors of the berry-hunters—these baffle description, yet we cannot pass them by in silence. The blood and orange splashed on black of the toucans, the scarlet and yellow of woodpeckers, the soft greens and buffs of flycatchers, all these paled when a flock of manakins or tanagers or honey-creepers came to the tree. Every precious stone found its counterpart in the metallic hues of these exquisite feathered folk.
The glory of all was the opal-crowned manakin, a midget in green coat and sulphur waistcoat, with a cap of scaly, iridescent, silvery mother-of-pearl plates, in no way akin to feathers. Until now the life of this Hop o' my Thumb, like those of all his ancestors, had gone smoothly on, with never a human to admire, to wonder, and vainly to echo the question of the great black frog, Wh—y?
On the last day of my stay I walked slowly up the trail toward the canella do matto. For the last time I strained upward at the well-known branches, and with the very movement there came the voice of the swamp. Its tone was insistent, with a tinge of accusation, a note of censure. Wh—y? and after a little time, Wh—y?
I looked about me despairingly. What had I learned after all? Was there any clearing up of the mystery of the jungle? Had my week of scrutiny brought me any closer to the real intimacies of evolution? Or—evading these questions for the time—was there nothing I could do in the few precious moments left?
In five minutes I should turn my back on all this wildness, this jungle seething with profound truths, and great solutions within arm's reach. I should pass to the ocean where monotony compels introspection, and finally to the great center of civilization where the veneer covers up all truths.