THE subject of bird language has been much discussed, frequently with a good deal of heat. At one time it was fashionable to deride the notion that birds might have a language of their own. The thought that most bird song, as distinguished from call notes, was strictly a courtship performance long held sway; but recently it has been more and more realized that song may also be used to establish the boundaries of a breeding territory. From my observations, I believe that bird notes can be divided into these several categories: —
1. Just chatter, such as humans indulge in at teas or cocktail parties.
2. Discussion of plans, such as might occur at a board meeting.
3. Maintenance of contact, such as the whistling of one partridge hunter to another in order that the proper position may be kept and that accidents may be avoided.
4. Warning of impending danger.
5. Courtship, including a “No Trespassing” sign.
6. Simple enjoyment, as one might play the piano for the fun of it.
At the risk of being called an “anthropomorphist,” I should like to illustrate and comment on these observations.
The best example of simple chatter among birds, in my experience, is that of a flock of feeding peep least or semipalmated sandpipers. Hidden in some near-by grass, I have often watched such a flock of peep scurrying hither and yon over freshly exposed mud flats. They keep up a constant little twittering and calling, sometimes interspersed with a louder, higher-pitched complaint as one, lazier and greedier than the others, tries to steal some tidbit from his neighbor. Occasionally, one of them will make a queer, trilling note, like the bouncing of a xylophone hammer. The whole effect always reminds me of those times when, as a boy, I was sick in an upstairs bed, while a tea party was going on below. Chatter, chatter, chatter.
I don’t think the peep do it simply to keep contact, although this may be so. Certainly, as all at once they take wing, the chattering ceases. I rather think they do it as a sort of comfort to themselves. It makes each individual feel that he is part of a large flock, where there is safety in numbers — or at least where the mathematical chances of sudden disaster are much reduced. It is the single, fast-flying peep which utters the characteristic shrill peep note.
There are many other birds that have a tendency to chatter. Offhand, I think of crossbills, siskins, cedar waxwings, and English sparrows. They are, of course, all birds which gather in flocks. In fact, I have an idea that all those birds which habitually feed in flocks have the chattering tendency.
Discussion of plans
There comes a day in the fall when the beetlehead (black-bellied plover) seem very restless. The wind is very likely fresh from the northwest and the air carries a distinct suggestion of winter. On such a day, the plaintive, musical call of these plover fills the marsh. Flocks of them, whistling loudly, will for no apparent reason rise up from a juicy-looking flat, and then quickly settle down again.
“Going to move on,” you say.
And you are quite right. Next morning, hardly is there one left. Plenty of yellow legs are about, and other shore birds, but no black-bellied plover.
Canada geese, I am pretty certain, communicate by voice. If one watches the actions of a flock, led by a big, white, old gander, especially if they are investigating what appears to be unknown territory, one can hardly escape the conclusion that the leader is giving orders. There is, of course, no way of telling whether the honking which goes back and forth between them is actually a discussion of plans. Certain it is, however, that the old gander may hold the flock high in the air, while he himself goes to investigate. I have seen this happen many times; and it seems inescapable that, when he is thoroughly satisfied, he calls them down by means of his voice.
Then again, it is interesting to watch a flock of geese, bound perhaps for the Carolinas, pass high above a flock feeding along our Cape Cod shores. Such a gabbling and a honking as then goes on!
“Don’t be foolish,” the migrating flock seems to say. “Come on south where it’s warm.”
“Mighty good eelgrass here, is the reply. “Why don’t you come down and stay awhile? Go south later, if you want to.”
Sometimes the high flock will waver, turn, and pitch down in. Sometimes the feeding flock will suddenly rise and follow along. More often, each flock will go its own way, and the noise will gradually subside.
But, of all the birds, crows appear to have the most complete system of communication, although I must admit that I am far from being able to understand it. My son Fred and I have spent many hours trying to learn their language, without too much success. There is one series of rather soft “caws” which we feel sure is a gather call — that is, a call for the gathering of a small group or unit, not the mobilization call for the entire crow population. It is usually uttered from some prominent place, like the roof of a house. Here eight or ton crows will convene. After a considerable period of cawing back and forth, one or two scouts are sent out to see where the best foraging for that day is to be had. Generally, in about fifteen minutes or so, the scouts come back to report. Then there is a great to-do, with all the crows talking at once. Apparently, however, they finally reach a decision, and one by one they fly off, always in the same direction and usually, if they can be followed through the glasses, to the same spot. One day it will be the Skiff Hill pastures; the next, the Beach Marsh; and so on.
All this may sound rather fanciful; but if one spends any considerable amount of time with them, one can hardly escape the conclusion that some birds, at least, have a very elaborate system of communication.
Maintenance of contact
Here again, crows are perhaps the best example. They appear to have definite outposts scattered over the countryside, one within hearing distance of the other. Let the big owl be found roosting in a pine tree and the call goes out. Crows can be seen flying toward the spot from every direction until there is a black mob of them, calling, pitching, badgering. At last the big gray bird becomes sick of the din and glides silently off to some more secure hiding place.
Another interesting fact is that there seem to be degrees of mobilization. A stray cat may call up only ten or fifteen crows; a red-tailed hawk, maybe twenty-five; while a big owl or a fox may bring literally hundreds down on himself. Surely the outposts, or liaison agents, must be able to indicate the severity of the emergency and whether local or general mobilization is indicated.
Of course, the commonest example of the use of bird voices for contact is the constant calling during migration. If one lies under the stars on the night of a big flight of small birds, he will find the air filled with a continuous series of chips and chirps as the tiny folk traverse the dark heavens.
In the fall one may see two or three bluebirds sitting on the peak of the barn roof. All around them, in the cedars, on the ground, on the south platform of the house, are hundreds of chipping sparrows and pine warblers, with perhaps a prairie or two, or some other warbler, in addition. Suddenly, the bluebirds begin their soft warble and, after a few moments, fly off. Then there starts up a tremendous chipping and chirping. Soon the pine warblers take wing, in ones and twos, followed more slowly by the sparrows, until the last straggler has gone and not a bird remains.
Obviously, this great loose flock, which may take many minutes to get under way, keeps itself together by means of constant calling. And the flock seems to be led by bluebirds, sometimes aided by a robin or two.
There can be no doubt that certain birds have calls which mean “Look out!” The scream of the blue jay, sometimes much to the annoyance of the hunter, is familiar to anyone who travels the woods. Nor is the significance of these calls limited to the species which make them. The blue jay’s scream, for instance, will alert not only all other birds within its range, but also all animals.
Not so well known is the alarm note of shore birds. I have never been quite able to attach any specific note to any specific species. I think the note, if heard by itself without all the attendant excitement, would readily identify the species. But as soon as it is uttered, there is a general turmoil. All the shore birds within hearing take wing. Large flocks of red-backed sandpipers will hurtle into the air and sweep off in a body, twisting this way and that with perfect precision, now gleaming white, now suddenly turning dark.
Sometimes, one may pick out with the glasses the cause of all this disturbance. Perhaps it is the peregrine, or duck hawk, whose lightning twists and turns always seem to be just a hair too late; or perhaps it is his smaller cousin, the merlin, or pigeon hawk; or possibly it is one of those roundwinged Accipiters, the sharp-shinned or the Cooper’s hawk.
For all of these the shore bird’s cry is the same. The note is shrill, very high pitched, and insistent. Once you have heard it, there is no mistaking it. Not always, however, can you find the marauder. The sharpness of vision of these shore birds is unbelievable, and their ability to identify their enemies almost more astonishing. I have heard a red-backed sandpiper give the warning cry when the dangerous falcon, to mere human eyes, was only a tiny speck in the sky.
Very different is the effect produced by our friend the marsh hawk. When the call goes out, it is much less emphatic. Only those shore birds which have chosen tide holes or shut-in creeks take wing. Those on the open flats merely suspend their search for food for a moment and cock a wary eye.
Occasionally, instead of flying when the alarm is given, a shore bird will “freeze.” I have seen a beetlehead, when the cry came, lie on his belly on the mud and draw in his neck so that he looked like nothing more than a hunk of seaweed. Only his sharp eye, tilted up toward the sky, could give him away.
There are many other birds, possibly all, which have a certain call that means “Watch out! Danger!” Whether one calls it bird language or not makes very little difference. There can be no question that when the call comes, most birds, and often some animals, pay heed. And usually it is well for them that they do!
The theory that song is used by many birds to establish territorial boundaries during the nesting season seems very reasonable and tends to be borne out by what I have observed. It is, however, quite impossible to tell how much of the song can be attributed to this purpose and how much to a courtship performance. Certainly, in many species, the males arrive first and are followed at some later date by the females. For instance, this is particularly true of robins. If one discounts flocks of wintering robins, so often seen in February, the very red breasted, dark headed males arrive some two weeks before the females. The male immediately starts trying to sing. His first attempts are often rather feeble, but after a few days he gets oiled up, and his joyous song from the near-by oak every morning ushers in the sunrise.
This early song appears to be chiefly territorial in purpose, for let another male come too close and a fight will ensue. Or if the robin should catch sight of his reflection in a windowpane, there may be a great to-do. But, when his lady arrives, who shall say that his song is not aimed at her? Certainly, a robin in full song would melt a heart of stone.
Other bird performances seem to me much more definitely a courtship act. The scream of the redshouldered hawk coming from high out of the air may represent a warning to other hawks; but his sudden, vertical plunge down to within a few feet of the treetops surely is done to impress his mate. The zooming boom of the night hawk, the flight performance of the woodcock, the drumming of the partridge, and the crow of the pheasant may serve both purposes, although I like to think of them as courtship activities.
To watch a pheasant crowing is quite an experience. He makes a mighty effort and produces a horrible squawk. This is accompanied and followed by a brief but rapid drumming of his wings. If you listen closely, on a still day, you can hear the drumming sound coming immediately after the crow.
Another courtship act which fascinates me is that of the bittern. One must admit that he is a funny-looking bird. He appears at his most ludicrous when, in attempting to hide, he stands thin and straight, with bill pointing toward the zenith. The light and dark stripes of his neck blend with the grass in which he is standing, and it takes a sharp eye to pick him out. Most people are familiar with his “song,” likened by some to the noise of the driving of a stake or the sucking of a pump. But it is much more than that. It has a rich, full-bodied quality as it comes booming out of a fresh-water marsh.
The bittern is so retiring that relatively few people ever see him perform. He goes through terrific contortions, as if he were becoming deathly ill, and then suddenly out comes the boom. Meanwhile, from somewhere at the base of his neck where they usually remain safely hidden, appear two long, white plumes. For some time, the bittern keeps up his pumping. Finally, perhaps from pure fatigue, he stops; and the white feathers vanish as mysteriously as they came.
Of recent years, we have had near the Farm House several pairs of nesting prairie horned larks. This tiny bird has a very insignificant song which I gather is not nearly as musical as his English cousin’s. However, he does his best by it. Up, up he flies, squeaking for all his might; higher and yet higher, until the eye, even with the aid of binoculars, can no longer follow, unless there should be handy a white cloud. For a long while, the squeaking goes on until all at once the little bird plunges down to the earth and lights close by the nest where his mate is sitting. Surely this, too, is a courtship performance.
Of all the bird songs, perhaps the crow’s song is the most definitely an act of wooing. So shy is he, however, that few people have ever heard him perform. I have talked with experienced field ornithologists who had never heard the crow’s song, and who, when I have spoken of it, have looked at me with disbelieving eyes. I myself have heard it only twice; and others who have told me of it have heard it only very rarely.
One day, my cousin and I were lazily paddling down the Ipswich River. There came from downstream of us that curious, staccato note of the crow — the one which resembles the rapid plucking of a taut string. Over and over, he repeated it.
“Keep quiet,” my cousin whispered. “Maybe he’ll sing for us.”
We drifted slowly downstream, making no motion and no sound. And then, just as we came around a bend, the crow began to sing. He and his ladylove were sitting near the top of a high pine and from his wide-open beak was coming a series of clear, bell-like notes. To me, they sounded both musical and sweet; and they certainly were as different from the crow’s normal voice as anything could be. Suddenly, the singer caught sight of us; and, with a series of protesting caws which to my imaginative ear contained a definite element of reproach, both crows flew off out of sight. Since then, only once have I heard the crow’s love song.
As a practical matter, I suppose it makes little difference whether bird song is mostly territorial in nature or is definitely directed toward obtaining and holding a mate. Certain it is that bird song reaches its peak during the nesting season. Here in Massachusetts, this occurs in late May, after which the singing gradually peters out. Early July may bring a slight recrudescence, but by the end of the month it has largely disappeared. Except for the indefatigable vireo, only an occasional whistle from an oriole or a hall hearted attempt by a robin interrupts the sleepy buzz of August locusts.
It seems to be unfashionable to suppose that birds, or animals for that matter, do anything just for the fun of it. I am sure, however, that frequently they do.
The hill and cedar bank which separate the Farm House from the Nausct Marsh face south. Come, then, when there is a good fresh southwester blowing and watch the herring gulls. They will start at the east, end of the cedar bank, meet the updraft, and with not a single wing-beat slide up along the brow of the hill, headed due west. However, when they come to where the hill drops down to the Salt Pond Creek, instead of scaling off across the Salt Pond and over to the Great Pond or perhaps the West Shore, as is often their custom, they make an abrupt turn to the east, coast off down to leeward, luff up over the east edge of the cedar bank, and slide by again. I have watched a single gull repeat this performance eight or ten times, and I cannot escape the notion that, like so many humans, gulls enjoy the haling of effortless travel.
As for singing for the fun of it, I can’t help thinking of the red-eyed vireo. He doesn’t have what could be called a beautiful song. In fact, it is so indefinite that one can listen to it for an hour or more without actually hearing it. Day in, day out, the incessantly repealed trio of notes goes on and on. It does not matter how hot or sultry the day, there is no minute of it when one cannot hear the vireo’s song. And he keeps it up way through the summer when other birds have become silent. I cannot believe the vireos do it for any other reason than that they like to. They remind me of a young lad, strolling aimlessly down the street, loudly whistling. Whatever the facts, I am quite sure the boy and the bird are doing it for the same reason. And I think that reason is that they just plain like the sound of it.
Of all the Farm House birds, the meadow larks seem to me the most representative. With us, they are permanent residents; and, in those rare years when there is long-standing snow on Outer Cape Cod, many of them die. About ten years ago, for instance, the Cape had one snowstorm after another, and the meadow larks practically disappeared. Now, however, they are more numerous than I have ever seen them. Last November we saw eighteen Hying in a loose flock — more than I have ever before seen together.
But it was of the meadow lark’s song that I particularly wished to speak. One may hear those clear, sweetly whistled notes in any month of the year — not so often in winter, perhaps, as in spring, but often enough to brighten the winter sky. Here is no question of maintaining territorial boundaries. Here is no question of nuptial activity. Surely, the meadow lark is singing for the simple joy of it, and because he is, no doubt, proud of his achievement.
As I lie in bed on a cold, still December day and wonder if I shall ever have the courage to leave it, suddenly from the top of a near-by cedar come those few clear notes. They make me feel ashamed of my laziness and I get up with a zest I would not otherwise have had. Perhaps, while the bacon is frying, even I break out into “song.” And this I do, I can assure one and all, neither to keep off trespassers — a method which, incidentally, might prove very effective — nor in order to impress my wife. I do it simply because I feel like it.
My guess is that birds sing for the same reason.