Our Bird Comrades Part 3

One autumn I found a number of these nuthatches a.s.sociated with a flock of myrtle warblers on the most sociable terms in a pine woodland not far from Pensacola, Florida. Now they were up in the trees, now down on the ground. All the while they were chirping in their most genial tones. In a spring jaunt to southern Mississippi, I was fortunate enough to find a nest in a half-decayed snag. It contained four of the prettiest half-fledged bird babies that have ever greeted my sight.

Oddly enough, our tiny clamberers utter a loud, shrill alarm-call that bears close resemblance to the querulous protest of the sparrow hawk as you approach her nest or young. Doctor Chapman says of the brown heads: "They are talkative sprites, and, like a group of school children, each one chatters away without paying the slightest attention to what his companions are saying."

The fourth member of the _Sittinae_ subfamily in America is the pigmy nuthatch, known scientifically as _Sitta pygmaea_, a genuine westerner, not known east of the plains. However, in the Rocky Mountain district he is an abundant species, his range east and west being from the plains to the Pacific coast, and north and south from the Canadian boundary to the mountains of Mexico. Swinging and gliding about among the pines, performing the same antics as his eastern kinsmen, he utters a cheery whistle, that may be translated, "Whit, whit, whit." His movements are often so rapid that he is difficult to follow with the eye as he flits from one tree to another or dashes amid the branches.

He scarcely remains quiet long enough for you to note his markings and settle his ident.i.ty, but once you are sure of him, you will never mistake him for another bird.

In Colorado there is little of a migratory movement even up and down the mountains among these interesting birdlets. In the winter a few descend from the heights and dwell on the plains, where the weather is not so rigorous. On the approach of spring they again hie up into the mountains, spending the summer there and rearing their pretty bairns.

However, the majority of them remain in the mountains all winter, braving the bitterest and fiercest storms, often at an alt.i.tude of 8,000 feet. Their breeding range is from 6,000 to 10,000 feet, the latter elevation being only a little below the timber line.

In spite of his unique and interesting habits, the poets have scarcely begun to chant the praises of the American nuthatch. One of the best tributes I have been able to find is from the pen of Edith Thomas, who apostrophizes our bird in this way:

"Shrewd little haunter of woods all gray, Whom I meet on my walk of a winter day, You're busy inspecting each cranny and hole In the ragged bark of yon hickory bole; You intent on your task, and I on the law Of your wonderful head and gymnastic claw!

"The woodp.e.c.k.e.r well may despair of this feat-- Only the fly with you can compete!

So much is clear; but I fain would know How you can so reckless and fearless go, Head upward, head downward, all one to you, Zenith and nadir the same to your view."

We have now described the American nuthatch quartette, and will turn to other fields no less inviting, albeit more remote. The nuthatch of central Europe, scientifically known as _Sitta caesia_, is closely related to our American forms, resembling them in many of his habits.

In studying the literature of the transatlantic species, we at once stumble upon the reason for calling this avian family by the somewhat peculiar and apparently inapt name of nuthatch. The older English form of the word was "nuthack," which unfortunately has been changed to "nuthatch," a word that gives an erroneous impression, for no bird ever hatches a nut. But with the last syllable "hack" the difficulty is all cleared up, as his habit of hacking or chipping nuts, which he places in c.h.i.n.ks of the bark or wall, is well known.

The nuthatch of England belongs to the species just named. He does not wear a black hood or mantle, but merely a black ribbon on the side of his head, enclosing the eye. His upper parts are bluish gray, save the outer tail feathers, which are black; his cheeks and throat are white, his breast and belly buff, and his flanks and lower tail-coverts chestnut red. A graphic English writer, Dr. W. H. Hudson, gives the following enthusiastic description of the little tobogganist of his native woodlands:

"When I see him sitting quite still for a few moments on a branch of a tree in his most characteristic nuthatch att.i.tude, on or under the branch, perched horizontally or vertically, with head or tail uppermost, but always with the body placed beetle-wise against the bark, head raised, and the straight, sharp bill pointed like an arm lifted to denote attention,--at such times he looks less like a living than a sculptured bird, a bird cut out of beautifully variegated marble--blue-gray, buff, and chestnut, and placed against the tree to deceive the eye. The figure is so smooth and compact, the tints so soft and stone-like; and when he is still, he is so wonderfully still, and his att.i.tude so statuesque! But he is never long still and when he resumes his lively, eccentric, up-and-down and sidewise motions, he is interesting in another way. He is like a small woodp.e.c.k.e.r who has broken loose from the woodp.e.c.k.e.r's somewhat narrow laws of progression, preferring to be a law unto himself.

"Without a touch of brilliant color, the nuthatch is a beautiful bird on account of the pleasing softness and harmonious disposition of his tints; and, in like manner, without being a songster in the strict sense of the word, his voice is so clear and far-reaching and of so pleasing a quality, that it often gives more life and spirit to the woods and orchards and avenues he frequents than that of many true melodists. This is more especially the case in the month of March, before the migratory songsters have arrived, when he is most loquacious. A high pitched, clear, ringing note, repeated without variation several times, is his most often-heard call or song. He will sometimes sit motionless on his perch, repeating this call at short intervals, for half an hour at a time. Another bird at a distance will be doing the same, and the two appear to be answering one another. He also has another call, not so loud and piercing, but more melodious: a double note, repeated two or three times, with something liquid and gurgling in the sound, suggesting the musical sound of lapsing water.

These various notes and calls are heard incessantly until the young are hatched, when the birds at once become silent."

The nesting habits of _caesia_ are quite similar to those of our American forms, with the following interesting exception: The doorway of the cavity const.i.tuting the bird's domicile is plastered up with clay, made viscid by the nuthatch's glutinous saliva, leaving in the center a circular hole just large enough to afford entrance and exit for the little owner. Says the author quoted above: "When the sitting bird is interfered with, she defends her treasures with great courage, hissing like a wryneck, and vigorously striking at her aggressor with her sharp bill." Like our common white-breast, the British bird may be attracted to human dwellings by furnis.h.i.+ng him a regular supply of food suited to his taste, and may grow so trustful as to come when called, and even to catch morsels thrown to him in the air. In the forest he often hammers so loudly on a resonant branch that his tattoo is mistaken for that of a woodp.e.c.k.e.r. The interior of the nest "contains a bed of dry leaves, or the filmy flakes of the inner bark of a fir or cedar, on which the eggs are laid."

In northern Europe another form of the nuthatch guild is found, known scientifically as _Sitta europea_, whose under parts are white without any was.h.i.+ng of buff on the breast.

The Levant furnishes a most charming addition to the feathered brotherhood now under consideration. The scientific gentlemen have christened it _Sitta syriaca_, and its common name is the rock nuthatch, an appellation that is most appropriate, for its chosen haunts are rocky cliffs, over the faces of which it scuttles in the most approved nuthatch fas.h.i.+on, head up or down, as the whim seizes it, clinging with its sharp claws to the c.h.i.n.ks, ledges, protuberances, and rough surfaces of the rocky walls. A little larger than its European cousin, its markings are quite similar. In Syria it is common as far north as the southern sh.o.r.es of the Black Sea. Although somewhat shy, it is described as having "sprightly manners and a clear, ringing trill." Odd indeed are some of nature's evolutions, I had almost said caprices, for the rock nuthatch is just as much at home and apparently just as happy on its bleak precipices as is our merry whitebreast in his umbrageous home in the oak or maple forest.

But what kind of nests do the rock nuthatches construct on their limestone walls? That is one of the most interesting features of the life of these birds. One writer[1] who has observed them in their native haunts describes the rock nuthatch as "an expert clay mixer and molder." The bird does not chisel out a nursery in the rock--no, indeed; his method of constructing his nest is as follows: Having found a little hollow or indentation on the rocky wall, he will erect a cap or dome of mortar over it, plastering the structure so firmly against the surface that no rain or storm or predaceous creeping thing can demolish it until long after it has been abandoned by the little architect. The circular base of the nest is ten or twelve inches in diameter. The dome is not entirely closed up, but a small orifice is left in the center, upon the edges of which a narrow neck or funnel, also made of mortar, is raised, the hole just large enough to admit the body of the bird. The funnel is about three inches long.

The building material employed is fine clay softened and glutinated with the bird's saliva and mixed with plant fibers, for the little mason does not believe in making bricks without straw. So well packed is the inch-thick wall that a stiff knife blade must be used to cut through it. While the natural color of the adobe cottage is ash-gray, and therefore harmonizes with the general hue of its surroundings, and also with the mezzotints of the builder, yet he sometimes decorates it with the gaily colored wings of moths caught in the chase and attached to the plaster while it is fresh. The rock nuthatch is as expert a mixer of mortar as the well-known cliff swallows of our own country, and his adobe dwellings bear a close resemblance to theirs.

It is interesting to note that the European nuthatch, while nesting regularly in tree cavities, sometimes also chooses the crannies of rocks, when he goes a little more extensively into the plastering business; but his skill is not so well developed as that of his oriental cousin, whose mud cottage is a model of its kind.

[1] The writer referred to is Mr. H. C. Tracy, to whose charming article in "The Wilson Bulletin," published at Oberlin, Ohio, I am indebted for all my material on the rock nuthatch.

A FEATHERED PARASITE*

*Reprinted from Appleton's "Popular Science Monthly," with additions.

Nothing could more clearly prove that a common law runs through the whole domain of Nature than the fact that in every division of her realm there seems to be a cla.s.s of parasites. In the vegetable world, as is well known, there are various plants that depend wholly on other plants for the supply of their vital forces. And in the human sphere there are parasites in a very real and literal sense--men and women who rely upon the toil and thrift of others to sustain them in worthless idleness.

In view of the almost universal character of this law it would be strange if these peculiar forms of dependence did not appear in the avian community. We do find such developments in that department of creation. Across the waters there is one bird that has won an unenviable reputation as a parasite: the European cuckoo relies almost wholly on the efforts of its more thrifty neighbors to hatch and rear its young, and thereby perpetuate the species. Strangely enough, our American cuckoos are not given to such slovenly habits, but build their own nests and faithfully perform the duties of nidification, as all respectable feathered folk should. However, this parasitical habit breaks out, quite unexpectedly, it must be conceded, in another American family of birds entirely distinct from the cuckoo group.

In America the cowbird, often called the cow bunting, is the only member of the avian household that spirits its eggs into the nests of other birds. The theory of evolution can do little toward accounting for the anomaly, and even if it should venture upon some suggestions it would still be just as difficult to explain the cause of the evolution in this special group, while all other avian groups follow the law of thrift and self-reliance.

[Ill.u.s.tration: Cowbird]

The cowbird belongs to the family of birds scientifically known as _Icteridae_, which includes such familiar species as the bobolinks, orioles, meadowlarks, and the various kinds of blackbirds, none of which, I am glad to say, are parasites. The name _Molothrus_ has been given to the genus that includes the cowbirds. They are confined to the American continent, having no a.n.a.logues in the lands across the seas. The same may be said, indeed, of the whole _Icteridae_ family.

It may be a matter of surprise to many persons that there are twelve species and subspecies of cowbirds in North and South America, for most of us are familiar only with the common cowbird (_Molothrus ater_) of our temperate regions. Of these twelve species only three are to be found within the limits of the United States, one is a resident of western Mexico and certain parts of Central America, while the rest find habitat exclusively in South America. A fresh field of investigation is open to some enterprising and ambitious naturalist who wishes to study several of these species, as comparatively little is known of their habits, and indeed much still remains to be learned of the whole genus, familiar as one or two of the species are. Their sly, surrept.i.tious manners render them exceedingly difficult to study at close range and with anything like satisfactory detail.

Are all of them parasites? Probably they are--at least to a greater or less degree--except one, the bay-winged cowbird of South America, which I shall reserve for notice later on in this chapter. We might a.s.sert that our common cowbirds are the parasites _par excellence_ of the family, for, so far as I can learn from reading and observation, they never build their own nests or rear their own young, but s.h.i.+ft all the duties of maternity, save the laying of the eggs, upon the shoulders of other innocent birds.

These avian "spongers" have a wide geographical range, inhabiting the greater part of the United States and southern Canada, except the extensive forest regions and some portions of the southern states.

They are most abundant in the states bordering on the upper Mississippi River and its numerous tributaries. On the Pacific coast west of the Cascade and Sierra Nevada mountains, they occur only as stragglers.

The most northern point at which they have been known to breed is the neighborhood of Little Slave Lake in southern Athabaska. In the autumn the majority of these birds migrate to southern Mexico, although a considerable number remain in our southern states, and a few occasionally tarry for the winter even as far north as New England and southern Michigan.

The male cowbird looks like a well-dressed gentleman--and may have even a slightly clerical air--in his closely fitting suit of glossy black, with its greenish and purplish iridescence, and his hood of rich metallic brown covering his head, neck, and chest. He makes a poor s.h.i.+ft as a musician, but his failure is not due to lack of effort, for during courts.h.i.+p days he does his level best to sing a variety of tunes, expanding and distorting his throat, fluffing up his feathers, spreading out his wings and tail, his purpose evidently being to make himself as fascinating as possible in the eyes of his lady love. One of his calls sounds like "spreele," piped in so piercing a key that it seems almost to perforate your brain.

One observer maintains that the cowbirds are not only parasitical in their habits, but are also absolutely devoid of conjugal affection, practicing polyandry, and seldom even mating. This is a serious charge, but it is doubtless true, for even during the season of courts.h.i.+p and breeding these birds live in flocks of six to twelve, the males almost always outnumbering the females. However, if their family relations are somewhat irregular, no one can accuse them of engaging in brawls, as so many other birds do, for both males and females seem to be on the most amicable terms with one another, and are, to all appearances, entirely free from jealousy. Who has ever seen two cowbirds fighting a duel like the orioles, meadowlarks, and robins?

In obtruding her eggs into the nests of other birds, Madame Cowbird is sly and stealthy. She does not drive the rightful owners from their nests, but simply watches her opportunity to drop her eggs into them when they are unguarded. No doubt she has been on the alert while her industrious neighbors have been constructing their domiciles, and knows where almost every nest in the vicinity is hidden. Says Major Charles Bendire: "In rare instances only will a fresh cowbird's egg be found among incubated ones of the rightful owners. I have observed this only on a single occasion." From one to seven eggs of the parasite are found in the nests of the dupes. In most cases the number is two, but in the case of ground builders the cowbird seems to have little fear of overdoing her imposition. Major Bendire says that he once found the nest of an oven-bird containing seven cowbird's eggs and only one of the little owner's.

If parasitism were the only crime of the cowbird one would not feel so much disposed to put her into the Newgate Calendar; but she not only inflicts her own eggs upon her innocent victims, but often actually tosses their eggs out of the nests in order to make room for her own.

Nor is that all; she will sometimes puncture the eggs of the owners to prevent their hatching, and thus increase the chances of her own offspring. Whether this is done with her beak or her claws is still an open question, Major Bendire inclining to the belief that it is done with the claws.

Her finesse is still further to be seen in the fact that she usually selects some bird for a victim that is smaller than herself, so that when her young hopefuls begin to grow they will be able to crowd or starve out the true heirs of the family. In this way it is thought that many a brood comes to an untimely end, the foster parents having no means of replacing their own little ones when they have been ejected from the nest. However, I doubt whether the cowbird's impositions are usually so destructive as some observers are inclined to believe. I once found a bush sparrow's nest containing one cowbird and four little sparrows, all of which were in a thriving condition. The sparrows were so well fed and active that as soon as I touched the nest they sprang, with loud chirping, over the rim of their cottage and scuttled away through the gra.s.s. They were certainly strong and healthy, in spite of the presence of their big foster brother. Before they flitted away I had time to notice how the little family were disposed. The cowbird was squatted in the center of the nest, while his little foster brothers and sisters were ranged around him, partly covering him and no doubt keeping him snug and warm. They were further advanced than he, for while they scrambled from the nest, he could do nothing but snuggle close on the bottom of the cup.

A wood thrush's nest that I found contained two young thrushes and two buntings. All of them were about half fledged. Being of nearly the same size, the queerly a.s.sorted bantlings lived in apparent peace in their narrow quarters. I watched them at frequent intervals, but saw no attempts on the part of the foundlings to crowd out their fellow-nestlings. The cowbirds were the first to leave the sylvan roof tree. Thus it appears that the intrusion of the cowbird's eggs does not always mean disaster to the real offspring of the brooding family, but of course it often prevents the laying of the full complement of eggs by the builders themselves.

Even after the youngsters have left the nest the mother cowbird does not a.s.sume the care of them, but still leaves them in charge of the foster parents. It is laughable, almost pathetic, to see a tiny oven-bird or redstart feeding a strapping young cowbird which is several times as large as herself. She looks like a pigmy feeding a giant. In order to thrust a tidbit into his mouth she must often stand on her tiptoes. Why the diminutive caterer does not see through the fraud I can not say. She really seems to be attached to the hulking youngster. By and by, however, when he grows large enough to s.h.i.+ft for himself, he deserts his little parents and nurses and seeks companions.h.i.+p among his own blood kindred, who doubtless bring him up in the way all cowbirds should go.

It is surprising how many species are imposed on successfully by the cowbird. The number, so far as has been observed, is ninety, with probably more to be added. Among the birds most frequently victimized are the phoebes, the song sparrows, the indigo birds, the bush sparrows, and the yellow-breasted chats. Even the nests of the red-headed woodp.e.c.k.e.r and the rock wrens are not exempt. Some species, notably the summer warblers, detect the imposture and set about defeating the purposes of the interloper by building another story to their little cottage, leaving the obtruded eggs in the cellar, where they do not receive enough warmth to develop the embryo.

While it is surprising that acute birds should allow themselves to be imposed on in this way, perhaps, after all, they look upon the cowbird as a kind of blessing in disguise; at least, he may not be an unmixed evil. They may act on the principle of reciprocity--that "one good turn deserves another." What I mean is this: In my rambles I have often found the cowbirds the first to give warning of the approach of a supposed danger. Having no domestic duties of their own, they can well secrete themselves in a tall tree overlooking the entire premises, and thus play the useful role of sentinel. This, I am disposed to believe, is one of the compensating uses of this parasite, and may furnish the reason for his being tolerated in birdland. And he is tolerated. Has any one ever seen other birds driving the cowbird away from their breeding precincts, or charging him with desperate courage, as they do the blue jays, the hawks, the owls, and other predatory species? He evidently subserves some useful purpose in the avian community, or he would not be treated with so much consideration.

A young cowbird that I purloined from the nest and tried to rear by hand did not prove a pleasant pet. He was placed in a large cage with several other kinds of young birds. At first he was quite docile, taking his food from my hand and even allowing some of his feathered companions to feed him; but in a few weeks he grew so wild and manifested such a fierce desire for the outdoor world that I was glad to carry him out to the woods and give him his freedom. A young red-winged blackbird and a pair of meadowlarks developed a different disposition.

The dwarf cow-bird (_Molothrus ater obscurus_) is similar to his relative just described, except that he is smaller and his geographical range is more restricted. He is a resident of Mexico, southern Texas, southwestern Arizona, and southern California. His habits resemble those of the common cowbird. Another bunting having almost the same range, although a little more southerly, is the red-eyed cowbird, which is larger and darker than our common cowbird and has the same parasitical habits.

In South America three species have been studied by Mr. W. H. Hudson, who, in collaboration with Mr. P. L. Sclater, has published a most valuable work on Argentine ornithology. One of these is called the Argentine cowbird (_Molothrus bonariensis_). It is a blue-blooded parasite, and has been seen striking its beak into the eggs of other birds and flying away with them. The males, it is said, show little discrimination in pecking the eggs, for they are just as likely to puncture the cowbird eggs as those of other birds. Every egg in a nest is frequently perforated in this way. These buntings lay a large number of eggs, often dropping them on the ground, laying them in abandoned nests, or depositing them in nests in which incubation has already begun, in which case all of them are lost. However, in spite of this wastefulness the birds thrive, thousands of them being seen in flocks during the season of migration.

And, by the way, a description of their habits by Mr. Hudson has thrown interesting light on the subject of migration in the southern hemisphere. South of the equator the recurrence of the seasons is the exact reverse of their recurrence north of the equator, and therefore the breeding season of the birds is in the autumn instead of the spring; the flight from winter cold occurs in the spring instead of in the autumn, and is toward the north instead of toward the south. Thus, in February and March the Argentine cowbirds are seen flying in vast battalions in the direction of the equatorial regions--that is, northward--in whose salubrious clime they spend the winter. As our northern autumn draws near and the southern spring approaches these winged migrants take the air line for their breeding haunts in the Argentine Republic and Patagonia. At the same time the migrants of the northern hemisphere are pressing southward before the bl.u.s.tering north wind. It all seems wonderful and solemn, this world-wide processional of the seasons and the birds.

Naturally one would expect to find some other eccentricities in this aberrant family besides that of parasitism, and in this expectation one is not disappointed. There are two other species of cowbirds in the Argentine country--the screaming cowbird (_Molothrus rufoaxillaris_) and the bay-winged cowbird (_Molothrus badius_). The latter is only partly a trencher on the rights of other birds--only half a parasite.

Indeed, it sometimes builds its own nest, which is quite a respectable affair; but, as if to prove that it still has some remnants of cowbird depravity in its nature, it frequently drives other birds from their rightful possessions, appropriates the quarters thus acquired, lays its eggs into them, and proceeds to the performance of its domestic duties like its respectable neighbors. Its virtue is that it never imposes the work of incubation and brood rearing on any of its feathered a.s.sociates, even though it does sometimes eject them from their premises.