SOUND MADE BY ANIMALS.

Dunstan Times, Issue 3372, 7 November 1927, Page 8

SOUND MADE BY ANIMALS.

A recent correspondent in the American scientific press on Singing Earthworms recalls the tact that much remains to be learnt as to the sounds produced by different kinds of animals, the organs producing them, and the part, if any, played by the sounds in the living routine of the creatures making them. The songs of birds have been much studied and written about, but probably even in that case more could be learned as to the family relationships of the different songs and calls. With other animals, except in such familiar cases as the domesticated races, the larger carnivora, deer, and so forth, very little is known (says Unscientific correspondent of the “Times”)- Hut there are gaps even in common knowledge; lovers of cats have-n-cognised that the Siamese race has a voice very different from that of the more common' breeds; does the voice suggest a different origin? The American correspondence, starting from observations published in German v, certainly used an extreme expression in speaking of the “singing of earthworms, and there were many who roundly denied the occurrence. But a competent observer, accustomed to study earthworms in the stillness ■of the night, when, as Darwin showed, earthworms protrude from their burows, states- that lie had long known of the faint “clicking sounds or stridulations” made by the worms, but had attributed these insignificant rustlings to the movements of the creatures in their burrows, or to possible escapes of air between the viscid lining of the burrow and the muscous surface of the body. But he removed them to damp sphagtim moss and found that they still produced the sounds. How they arc produced and what part they play arc unascertained. So also except for insects, in the great majority of the invertebrates nothing whatever is known as to the capacity for producing sounds. That noises have not been heard does not imply their absence, because in this hungry world the first business of most animals is to avoid calling attention to their existence. Many surface-feeding fish, as, for example, carp, make an unpleasant gulping noise when they suck in food, but this' seems to be an accidental sound. Some marine fishes, especially those with open swim bladders, are reported to make a noise when they come to the surface, possibly due to the extrusion of gas from the swim bladder, but no exact observations have been made. The clamorous voice of the frogs is Avell known and has been studied carefully, so that experts can tell the species from the sound. In some eases (he notes are definitely sexual calls; in others apparently no more than an expression of the exuberant vitality of the breeding season. The tailless amphibia are generally reputed to, be silent, but careful observers of the common smooth newt of this country have heard it utter a gentle little pipe when it thrusts its head above the surface of the pond, and doubtless other newts are not all voiceless. Most persons would tell you that the voice of reptiles is only an angry hiss, and this seems to be true of the snakes. But some lizards are noisy, the sharp cluck of geckos and “tuctoOs” being a family character. Tortoises and turtles hiss in the reptilian fashion, but in the breeding season many of the larger tortoises utter very loud sounds recalling the rejoicing notes of a hen when she has laid an egg. Crocodiles and alligators emit a kind of hiss, but they have also a loud roar, heard usually at night or early in the morning, each species with a characteristic nluation, but all recalling the roar of a lion. Not knowing this the present writer and his companions, camping in the South Sudan, believed themselves surrounded by unfriendly lions, and with much trouble kept a fire going all night when, without doubt, the voice was that of crocodiles engaged on thenown business in the valley of the Nile, three miles away.

Marsupials, with the exception of the thylacine or Tasinnniiui “wolf,” and the Tasmanian “devil,” have the repu. tntion of being silent creatures, and some Australian naturalists have even refused loud voices to these two notorious cases. But the “wolf” at any time utters a long h ( owl, rising and falling in an excessively wild and melancholy fashion, but quite unlike the howl of dogs or wolves.. The “devils” might have got their popular name from their voices; their clamour is always in company and seems to be an expression of murderous crime, but if it be possible to creep up to them without disturbing them they are found lo all appearances engaged only in friendly conversation. The herbivorous marsupials arc usually silent, and kangaroos, even when they are fighting or making love do not give voice. But a kangaroo when frightened, as for instance, when it is being held to be given an anaesthetic, howls as loudly .iiul mill'll in the same fashion as the thylacine—an interesting example oi the clues to affinity which might be got from a comparative study of voice. Very probably the vast majority of mammals have characteristic voices of several kinds. Hyraxcs not only stamp with their feet on the ground, but emit a kind of hiss when they are demonstrating against an enemy, when pleased they have a gentle and very soft twitter, partly a purr and partly a song; at night they have a resounding yell, which echoes in the trees like the voices of lost souls. Capybaras, playing together, maintain a continuous little plaintive note inaudible *a few yards off. Antelopes all grunt, possibly they have other voices, but at least in captivity they have not been heard. Examples could be multiplied, but the ■whole matter requires careful investigation, first merely as a series of observations recorded by gramophone, and then submitted to comparison.