Sociability—that is, the need of the animal of associating with its like—the love of society for society’s sake, combined with the “joy of life,” only now begins to receive due attention from the zoologists.50 We know at the present time that all animals, beginning with the ants, going on to the birds, and ending with the highest mammals, are fond of plays, wrestling, running after each other, trying to capture each other, teasing each other, and so on. And while many plays are, so to speak, a school for the proper behaviour of the young in mature life, there are others, which, apart from their utilitarian purposes, are, together with dancing and singing, mere manifestations of an excess of forces—“the joy of life,” and a desire to communicate in some way or another with other individuals of the same or of other species—in short, a manifestation of sociability proper, which is a distinctive feature of all the animal world.51 Whether the feeling be fear, experienced at the appearance of a bird of prey, or “a fit of gladness” which bursts out when the animals are in good health and especially when young, or merely the desire of giving play to an excess of impressions and of vital power—the necessity of communicating impressions, of playing, of chattering, or of simply feeling the proximity of other kindred living beings pervades Nature, and is, as much as any other physiological function, a distinctive feature of life and impressionability. This need takes a higher development and attains a more beautiful expression in mammals, especially amidst their young, and still more among the birds; but it pervades all Nature, and has been fully observed by the best naturalists, including Pierre Huber, even amongst the ants, and it is evidently the same instinct which brings together the big columns of butterflies which have been referred to already.
The habit of coming together for dancing and of decorating the places where the birds habitually perform their dances is, of course, well known from the pages that Darwin gave to this subject in The Descent of Man (ch. xiii). Visitors of the London Zoological Gardens also know the bower of the satin bowerbird. But this habit of dancing seems to be much more widely spread than was formerly believed, and Mr. W. Hudson gives in his master-work on La Plata the most interesting description, which must be read in the original, of complicated dances, performed by quite a number of birds: rails, jacanas, lapwings, and so on.
The habit of singing in concert, which exists in several species of birds, belongs to the same category of social instincts. It is most strikingly developed with the chakar (Chauna chavarris), to which the English have given the most unimaginative misnomer of “crested screamer.” These birds sometimes assemble in immense flocks, and in such cases they frequently sing all in concert. W. H. Hudson found them once in countless numbers, ranged all round a pampas lake in well-defined flocks, of about 500 birds in each flock.
“Presently,” he writes, “one flock near me began singing, and continued their powerful chant for three or four minutes; when they ceased the next flock took up the strains, and after it the next, and so on, until once more the notes of the flocks on the opposite shore came floating strong and clear across the water—then passed away, growing fainter and fainter, until once more the sound approached me travelling round to my side again.”
On another occasion the same writer saw a whole plain covered with an endless flock of chakars, not in close order, but scattered in pairs and small groups. About nine o’clock in the evening, “suddenly the entire multitude of birds covering the marsh for miles around burst forth in a tremendous evening song. … It was a concert well worth riding a hundred miles to hear.”52 It may be added that like all sociable animals, the chakar easily becomes tame and grows very attached to man. “They are mild-tempered birds, and very rarely quarrel”—we are told—although they are well provided with formidable weapons. Life in societies renders these weapons useless.
That life in societies is the most powerful weapon in the struggle for life, taken in its widest sense, has been illustrated by several examples on the foregoing pages, and could be illustrated by any amount of evidence, if further evidence were required. Life in societies enables the feeblest insects, the feeblest birds, and the feeblest mammals to resist, or to protect themselves from, the most
