These two things—the one difficult, the other apparently impossible—the bird has realized.
At first, association and government. Monarchy is the inferior venture. Just as the apes have a king to conduct each band, several species of birds, especially in dangerous emergencies, appear to follow a chief.
The ant-eaters have a king; so have the birds of paradise. The tyrant, an intrepid little bird of extraordinary audacity, affords his protection to some larger species, which follow and confide in him. It is asserted that the noble hawk, repressing its instincts of prey for certain species, allows the trembling families which trust in his generosity to nestle under and around him.
But the safest fellowship is that between equals. The ostrich, the penguin, a crowd of species, unite for this purpose. Several kinds, associating for the purpose of travel, form, at the moment of emigration, into temporary republics. We know the good understanding, the republican gravity, the perfect tactic of the storks and cranes. Others, smaller in size or less completely armed—in climates, moreover, where nature, cruelly prolific, engenders without pause their formidable foes—place their abodes close together, but do not mingle them, and under a common roof, living in separate partitions, form veritable hives.
The description given by Paterson appeared fabulous; but it has been confirmed by Levaillant, who frequently encountered in Africa, studied, and investigated the strange community. The engraving given in the "Architecture of Birds" enables the reader more readily to comprehend his narration. It is the image of an immense umbrella planted on a tree, and shading under its common roof more than three hundred habitations. "I caused it to be brought to me," says Levaillant, "by several men, who set it on a vehicle. I cut it with an axe, and saw that it was in the main a mass of Booschmannie grass, without any mixture, but so strongly woven together that it was impossible for the rain to penetrate. This is only the framework of the edifice; each bird constructs for himself a separate nest under the common pavilion. The nests occupy only the reverse of the roof; the upper part remains empty, without, however, being useless; for, raised more than the remainder of the pile, it gives to the whole a sufficient inclination, and thus preserves each little habitation. In two words, let the reader figure to himself a great oblique and irregular roof, whose edge in the interior is garnished with nests ranged close to one another, and he will have an exact idea of these singular edifices.
"Each nest is three or four inches in diameter, which is sufficiently large for the bird; but as they are in close contact around the roof, they appear to the eye to form but a single edifice, and are only separated by a small opening which serves as an entry to the nest; and one entrance frequently is common to three nests, one of which is placed at the bottom, and the others on each side. It has 320 cells, and will hold 640 inhabitants, if each contains a couple, which may be doubted. Every time, however, that I have aimed at a swarm, I have killed the same number of males and females."
A laudable example, and worthy of imitation! I wish I could but believe that the fraternity of those poor little ones was a sufficient protection. Their number and their noise may sometimes alarm the enemy, disturb the monster, make him take another direction. But if he should persist; if, strong in his scaly skin, the boa, deaf to their cries, mounts to the attack, invades the city at the time when the fledglings have as yet no wings for flight, their numbers then can but multiply the victims.
There remains the idea of Aristophanes, the aerial city—to isolate it from earth and water, and build in the air.