All sounds have ceased save the booming of the frogs, which but emphasises the loneliness of it all. A distant whistle of a locomotive dispels the idea that all the world is wilderness. The firefly lamps glow along the margin of the rushes. The frogs are now in full chorus, the great bulls beating their tom-toms and the small fry filling in the c.h.i.n.ks with shriller cries. How remote the scene and how melancholy the chorus!
To one mind there is a quality in the frogs" serenade that strikes the chord of sadness, to another the chord of contentment, to still another it is the chant of the savage, just as the hoot of an owl or the bark of a fox brings vividly to mind the wilderness.
Out of the night comes softly the croon of a little screech owl--that cry almost as ancient as the hills. It belongs with the soil beneath our towns. It is the spirit of the past crying to us. So the dirge of the frog is the cry of the spirit of river and marshland.
Our robins and bluebirds are of the orchard and the home of man, but who can claim neighbourship to the bittern or the bullfrog? There is nothing of civilisation in the hoa.r.s.e croak of the great blue heron. These are all barbarians and their songs are of the untamed wilderness.
The moon rises over the hills. The mosquitoes have become savage. The marsh has tolerated us as long as it cares to, and we beat our retreat.
The night hawks swoop down and boom as they pa.s.s overhead. One feels thankful that the mosquitoes are of some good in furnishing food to so graceful a bird.
A water snake glides across the channel, leaving a silver wake in the moonlight. The frogs plunk into the water as we push past. A night heron rises from the margin of the river and slowly flops away. The bittern booms again as we row down the peaceful river, and we leave the marshland to its ancient and rightful owners.
And the marsh is meshed with a million veins, That like as with rosy and silvery essences flow In the rose and silver evening glow.
Farewell, my lord Sun!
The creeks overflow; a thousand rivulets run "Twixt the roots of the sod; the blades of the marsh gra.s.s stir; Pa.s.seth a hurrying sound of wings that westward whirr.
Sidney Lanier.
THE COMING OF MAN
If we betake ourselves to the heart of the deepest forests which are still left upon our northern hills, and compare the bird life which we find there with that in the woods and fields near our homes, we shall at once notice a great difference. Although the coming of mankind with his axe and plough has driven many birds and animals far away or actually exterminated them, there are many others which have so thrived under the new conditions that they are far more numerous than when the tepees of the red men alone broke the monotony of the forest.
We might walk all day in the primitive woods and never see or hear a robin, while in an hour"s stroll about a village we can count scores. Let us observe how some of these quick-witted feathered beings have taken advantage of the way in which man is altering the whole face of the land.
A pioneer comes to a spot in the virgin forest which pleases him and proceeds at once to cut down the trees in order to make a clearing. The hermit thrush soothes his labour with its wonderful song; the pileated woodp.e.c.k.e.r pounds its disapproval upon a near-by hollow tree; the deer and wolf take a last look out through the trees and flee from the spot forever. A house and barn arise; fields become covered with waving gra.s.s and grain; a neglected patch of burnt forest becomes a tangle of blackberry and raspberry; an orchard is set out.
When the migrating birds return, they are attracted to this new scene. The decaying wood of fallen trees is a paradise for ants, flies, and beetles; offering to swallows, creepers, and flycatchers feasts of abundance never dreamed of in the primitive forests. Straightway, what must have been a cave swallow becomes a barn swallow; the haunter of rock ledges changes to an eave swallow; the nest in the niche of the cliff is deserted and phoebe becomes a bridgebird; cedarbirds are renamed cherrybirds, and catbirds and other low-nesting species find the blackberry patch safer than the sweetbrier vine in the deep woods. The swift leaves the lightning-struck hollow tree where owl may harry or snake intrude, for the chimney flue--sooty but impregnable.
When the great herds of ruminants disappear from the western prairies, the buffalo birds without hesitation become cowbirds, and when the plough turns up the never-ending store of grubs and worms the birds lose all fear and follow at the very heels of the plough-boy: grackles, vesper sparrows, and larks in the east, and flocks of gulls farther to the westward.
The crow surpa.s.ses all in the keen wit which it pits against human invasion and enmity. The farmer declares war (all unjustly) against these sable natives, but they jeer at his gun and traps and scarecrows, and thrive on, killing the noxious insects, devouring the diseased corn-sprouts,--doing great good to the farmer in spite of himself.
The story of these sudden adaptations to conditions which the birds could never have foreseen is a story of great interest and it has been but half told. Climb the nearest hill or mountain or even a tall tree and look out upon the face of the country. Keep in mind you are a bird and not a human,--you neither know nor understand anything of the reason for these strange sights,--these bipeds who cover the earth with great square structures, who scratch the ground for miles, who later gnaw the vegetation with great shining teeth, and who are only too often on the look out to bring sudden death if one but show a feather. What would you do?
THE SILENT LANGUAGE OF ANIMALS
What a great difference there is in brilliancy of colouring between birds and the furry creatures. How the plumage of a cardinal, or indigo bunting, or hummingbird glows in the sunlight, and reflects to our eyes the most intense vermilion or indigo or an iridescence of the whole gamut of colour. On the other hand, how sombrely clad are the deer, the rabbits, and the mice; gray and brown and white being the usual hue of their fur.
This difference is by no means accidental, but has for its cause a deep significance,--all-important to the life of the bird or mammal. Scientists have long known of it, and if we unlock it from its hard sheathing of technical terms, we shall find it as simple and as easy to understand as it is interesting. When we once hold the key, it will seem as if scales had fallen from our eyes, and when we take our walks abroad through the fields and woods, when we visit a zoological park, or even see the animals in a circus, we shall feel as though a new world were opened to us.
No post offices, or even addresses, exist for birds and mammals; when the children of the desert or the jungle are lost, no detective or policeman hastens to find them, no telephone or telegraph aids in the search. Yet, without any of these accessories, the wild creatures have marvellous systems of communication. The five senses (and perhaps a mysterious sixth, at which we can only guess) are the telephones and the police, the automatic sentinels and alarms of our wild kindred. Most inferior are our own abilities in using eyes, nose, and ears, when compared with the same functions in birds and animals.
Eyes and noses are important keys to the bright colours of birds and comparative sombreness of hairy-coated creatures. Take a dog and an oriole as good examples of the two extremes. When a dog has lost his master, he first looks about; then he strains his eyes with the intense look of a near-sighted person, and after a few moments of this he usually yelps with disappointment, drops his nose to the ground, and with unfailing accuracy follows the track of his master. When the freshness of the trail tells him that he is near its end he again resorts to his eyes, and is soon near enough to recognise the face he seeks. A fox when running before a hound may double back, and make a close reconnaissance near his trail, sometimes pa.s.sing in full view without the hound"s seeing him or stopping in following out the full curve of the trail, so completely does the wonderful power of smell absorb the entire attention of the dog.
Let us now turn to the oriole. As we might infer, the nostrils incased in horn render the sense of smell of but slight account. It is hard to tell how much a bird can distinguish in this way--probably only the odour of food near at hand. However, when we examine the eye of our bird, we see a sense organ of a very high order. Bright, intelligent, full-circled, of great size compared to the bulk of the skull, protected by three complete eyelids; we realise that this must play an important part in the life of the bird. There are, of course, many exceptions to such a generalisation as this. For instance, many species of sparrows are dull-coloured. We must remember that the voice--the calls and songs of birds--is developed to a high degree, and in many instances renders bright colouring needless in attracting a mate or in locating a young bird.
As we have seen, the sense of smell is very highly developed among four-footed animals, but to make this efficient there must be something for it to act upon; and in this connection we find some interesting facts of which, outside of scientific books, little has been written. On the entire body, birds have only one gland--the oil gland above the base of the tail, which supplies an unctuous dressing for the feathers. Birds, therefore, have not the power of perspiring, but compensate for this by very rapid breathing. On the contrary, four-footed animals have glands on many portions of the body. Nature is seldom contented with the one primary function which an organ or tissue performs, but adjusts and adapts it to others in many ingenious ways. Hence, when an animal perspires, the pores of the skin allow the contained moisture to escape and moisten the surface of the body; but in addition to this, in many animals, collections of these pores in the shape of large glands secrete various odours which serve important uses. In the skunk such a gland is a practically perfect protection against attacks from his enemies. He never hurries and seems not to know what fear is--a single wave of his conspicuous danger signal is sufficient to clear his path.
In certain species of the rhinoceros there are large glands in the foot.
These animals live among gra.s.s and herbage which they brush against as they walk, and thus "blaze" a plain trail for the mate or young to follow.
There are few if any animals which care to face a rhinoceros, so the scent is incidentally useful to other creatures as a warning.
It is believed that the hard callosities on the legs of horses are the remains of glands which were once upon a time useful to their owners; and it is said that if a paring from one of these hard, h.o.r.n.y structures be held to the nose of a horse, he will follow it about, hinting, perhaps, that in former days the scent from the gland was an instinctive guide which kept members of the herd together.
"Civet," which is obtained from the civet cat, and "musk," from the queer little hornless musk deer, are secretions of glands. It has been suggested that the defenceless musk deer escapes many of its enemies by the similarity of its secretion to the musky odour of crocodiles. In many animals which live together in herds, such as the antelope and deer, and which have neither bright colours nor far-reaching calls to aid straying members to regain the flock, there are large and active scent glands. The next time you see a live antelope in a zoological park, or even a stuffed specimen, look closely at the head, and between the eye and the nostril a large opening will be seen on each, side, which, in the living animal, closes now and then, a flap of skin shutting it tight.
Among pigs the fierce peccary is a very social animal, going in large packs; and on the back of each of these creatures is found a large gland from which a clear watery fluid is secreted. Dogs and wolves also have their odour-secreting glands on the back, and the "wolf-pack" is proverbial.
The gland of the elephant is on the temple, and secretes only when the animal is in a dangerous mood, a hint, therefore, of opposite significance to that of the herding animals, as this says, "Let me alone! stay away!"
Certain low species of monkeys, the lemurs, have a remarkable bare patch on the forearm, which covers a gland serving some use.
If we marvel at the keenness of scent among animals, how incredible seems the similar sense in insects--similar in function, however different the medium of structure may be. Think of the scent from a female moth, so delicate that we cannot distinguish it, attracting a male of the same species from a distance of a mile or more. Entomologists sometimes confine a live female moth or other insect in a small wire cage and hang it outdoors in the evening, and in a short time reap a harvest of gay-winged suitors which often come in scores, instinctively following up the trail of the delicate, diffused odour. It is surely true that the greatest wonders are not always a.s.sociated with mere bulk.
INSECT MUSIC
Among insects, sounds are produced in many ways, and for various reasons.
A species of ant which makes its nest on the under side of leaves produces a noise by striking the leaf with its head in a series of spasmodic taps, and another ant is also very interesting as regards its sound-producing habit. "Individuals of this species are sometimes spread over a surface of two square yards, many out of sight of the others; yet the tapping is set up at the same moment, continued exactly the same s.p.a.ce of time, and stopped at the same instant. After the lapse of a few seconds, all recommence simultaneously. The interval is always approximately of the same duration, and each ant does not beat synchronously with every other ant, but only like those in the same group, so the independent tappings play a sort of tune, each group alike in time, but the tapping of the whole ma.s.s beginning and ending at the same instant. This is doubtless a means of communication."
The organ of hearing in insects is still to be discovered in many forms, but in katydids it is situated on the middle of the fore-legs; in b.u.t.terflies on the sides of the thorax, while the tip of the horns or antennae of many insects is considered to be the seat of this function. In all it is little more than a cavity, over which a skin is stretched like a drum-head, which thus reacts to the vibration. This seems to be very often "tuned," as it were, to the sounds made by the particular species in which it is found. A cricket will at times be unaffected by any sound, however loud, while at the slightest "screek" or chirp of its own species, no matter how faint, it will start its own little tune in all excitement.
The songs of the cicadas are noted all over the world. Darwin heard them while anch.o.r.ed half a mile off the South American coast, and a giant species of that country is said to produce a noise as loud as the whistle of a locomotive. Only the males sing, the females being dumb, thus giving rise to the well-known Grecian couplet:
"Happy the cicadas" lives, For they all have voiceless wives."
Anyone who has entered a wood where thousands of the seventeen-year cicadas were hatching has never forgotten it. A threshing machine, or a gigantic frog chorus, is a fair comparison, and when a branch loaded with these insects is shaken, the sound rises to a shrill screech or scream.
This noise is supposed--in fact is definitely known--to attract the female insect, and although there may be in it some tender notes which we fail to distinguish, yet let us hope that the absence of any highly organised auditory organ may result in reducing the effect of a steam-engine whistle to an agreeable whisper! It is thought that the vibrations are felt rather than heard, in the sense that we use the word "hear"; if one has ever had a cicada _zizz_ in one"s hand, the electrical shocks which seem to go up the arm help the belief in this idea. To many of us the song of the cicada--softened by distance--will ever be pleasant on account of its a.s.sociations. When one attempts to picture a hot August day in a hay-field or along a dusty road, the drowsy _zee-ing_ of this insect, growing louder and more accelerated and then as gradually dying away, is a focus for the mind"s eye, around which the other details instantly group themselves.
The apparatus for producing this sound is one of the most complex in all the animal kingdom. In brief, it consists of two external doors, capable of being partly opened, and three internal membranes, to one of which is attached a vibrating muscle, which, put in motion, sets all the others vibrating in unison.
We attach a great deal of importance to the fact of being educated to the appreciation of the highest cla.s.s of music. We applaud our Paderewski, and year after year are awed and delighted with wonderful operatic music, yet seldom is the _limitation_ of human perception of musical sounds considered.
If we wish to appreciate the limits within which the human ear is capable of distinguishing sounds, we should sit down in a meadow, some hot midsummer day, and listen to the subdued running murmur of the myriads of insects. Many are very distinct to our ears and we have little trouble in tracing them to their source. Such are crickets and gra.s.shoppers, which fiddle and rasp their roughened hind legs against their wings. Some b.u.t.terflies have the power of making a sharp crackling sound by means of hooks on the wings. The katydid, so annoying to some in its persistent ditty, so full of reminiscences to others of us, is a large, green, fiddling gra.s.shopper.
Another sound which is typical of summer is the hum of insects" wings, sometimes, as near a beehive, rising to a subdued roar. The higher, thinner song of the mosquito"s wings is unfortunately familiar to us, and we must remember that the varying tone of the hum of each species may be of the greatest importance to it as a means of recognition. Many beetles have a projecting horn on the under side of the body which they can snap against another projection, and by this means call their lady-loves, literally "playing the bones" in their minstrel serenade.
Although we can readily distinguish the sounds which these insects produce, yet there are hundreds of small creatures, and even large ones, which are provided with organs of hearing, but whose language is too fine for our coa.r.s.e perceptions. The vibrations--chirps, hums, and clicks--can be recorded on delicate instruments, but, just as there are shades and colours at both ends of the spectrum which our eyes cannot perceive, so there are tones running we know not how far beyond the scale limits which affect our ears. Some creatures utter noises so shrill, so sharp, that it pains our ears to listen to them, and these are probably on the borderland of our sound-world.