The Zoologist/4th series, vol 6 (1902)/Issue 733/Avicultural Experiences during about Twenty Years' Study of Birds in Captivity

by Arthur Gardiner Butler

 

THE ZOOLOGIST

 

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No. 733.—July, 1902.

 

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AVICULTURAL EXPERIENCES DURING ABOUT
TWENTY YEARS' STUDY OF BIRDS IN CAP-
TIVITY.

By Arthur G. Butler, Ph.D.

 

It is now about thirty-one years since I first commenced the study of living birds, and about twenty years since I first began to keep them in cage and aviary. During the whole of that time I have striven to make this labour of love useful to ornithologists generally; not only by carefully noting the behaviour of the various species which I have possessed—their postures when courting, their songs, their changes of plumage, and the manner in which those changes were effected, the colouring of their soft parts, their sexual differences, their method of nesting, and the character of their eggs—but I have, I think, conclusively proved that birds, although they undoubtedly are guided by instinct (by which term I understand inherited impressions upon the brain), are nevertheless capable of reasoning, and altering their inherited habit to suit a changed environment. I have also found that a bird, when hand-reared, and constantly in the company of human beings, develops a higher order of intelligence, and consequently is capable of a keener enjoyment of life, than if permitted to grow up a savage.

The postures, bowings, and dances of birds when courting are generally exceedingly comical, and, if birds regarded them from a human standpoint, they would be better calculated to inspire a feeling of scorn than of admiration in the minds of their mates; though in some cases, where brilliant colouring is thereby exposed to the feminine eye, admiration might modify the contemptuous feeling.

Among the Thrushes, the cock birds usually approach the hens with outstretched neck, drooping wings, and tail jerked upright. After pairing the cock bird stands straight up, with tail depressed, neck stretched, and bill in a line with the neck, and utters a screaming whistle. I have noticed this in the case both of the American Blue-bird (Sialia sialis) and the common Blackbird, the latter being a wild bird, which used to approach its hen upon the roof of my outdoor aviary, which runs parallel to the side of my conservatory.

The dances and postures of the Satin Bower-bird (Ptilorhynchus violaceus) are always accompanied by a continuous song, like water escaping down a sink or gully; even the checks, occasioned by bits of leaf or stick in the water, are admirably rendered. At intervals, when the bird takes a lateral hop, or changes its position, the gurgling and sizzling notes are interrupted by hoarse screaming whistles. The postures are a good deal varied; a common type is represented by the neck being somewhat retracted, the feathers of the nape and back raised, the tail span-roofed, drooped, the wings lifted alternately, whilst the bird sways from side to side. In another dance the head is stretched forward, the body held high, with all the feathers tightly appressed, but the tail still drooping. A third position is represented by the bird gazing fixedly at its mate, with the bill nearly touching the earth; the bird often carries a feather, dead leaf, or piece of food in its mouth when going through its performance, and its changes of form and posture are quick and startling.

One thing has astonished me somewhat with regard to this species: I find that both sexes, at different times, indulge in the same performances, both in dancing and singing, and whichever sex happens to be going through its evolutions is a source of terror to the other. As both my birds acquired their very dissimilar adult colouring in September, 1900, there can be no question as to their being genuine male and female.

Touching this acquirement of the colouring which has given to this Bower-bird its very appropriate name, a most astounding statement has been made by the Director of the Zoological Gardens at Melbourne. He asserts "that the birds only come to their full plumage in old age," and that "they die off shortly after the change."^[1] Such an idea is contrary to all our experience of bird-life, and is certainly disproved in the case of those males of the Satin Bower-bird which have assumed their full colouring in England.

In the true Finches (Fringillidæ), the methods of subduing the females are very varied; the Chaffinches and Saffron-Finches (Fringilla and Sycalis) are very rough wooers; they sing vociferously, and chase their hens violently, knocking them over in their flight, pursuing and savagely pecking them even on the ground; but when once the hens become submissive, the males change their tactics, and become for the time model husbands, feeding their wives from the crop, after the fashion of the Serins, and assisting in rearing the young.

Although the hens of Saffron-Finches (Sycalis flaveola and pelzelni) frequently pursue and peck unpaired cock birds, I do not think they ever kill them, as one cock will often kill another, by tearing back the scalp from the base of the beak; but I have known a cock S. flaveola to kill his wife, who had already brought up two families, because she was disinclined to continue her labours.

The Serins (Serinus) seem to depend chiefly upon their song to captivate their brides; there is often a little chasing and quarrelling on both sides, if the hen is not inclined to undertake marital duties; as soon as she is, she sits upon a perch quivering or flapping her wings, and with her head thrown backwards. You may notice the same thing with Sparrows and many other Finches after they have once paired; but the cock Sparrows have a regular dance, with drooped wings and erected tail, which I have observed in no other Fringillidæ, though there may be other typical Finches which dance to their mates.

The Buntings chase their partners violently, singing all the while, after the manner of the Saffron-Finches, but without the same spite; and on more than one occasion I have had males of Paroaria which, when courting, plucked their breasts nearly bare of feathers; whether this was to show their bravery, or to offer building materials for the new home, I never could determine; it certainly did not render them more attractive to me, however it may have struck the hen Cardinals.

Among the Weaving-Finches (Ploceidæ) dancing is common, and the attitudes assumed by some of the species when singing and dancing to their mates are very ludicrous. The genera of Ploceidæ, if judged by their habits and songs, are strangely commingled in systematic works; but to the aviculturist they readily sort themselves into the groups known as Waxbills, of which Estrilda is the typical genus; Grass-Finches (=Amadina), and many others; Mannikins, of which Munia is typical; Whydahs =Vidua and allies; and true Weavers—Ploceus, Pyromelana, &c. The true Waxbills, when showing off and singing, usually take a long grass-stem in their beaks, grasp the perch firmly, look straight upwards, and raise themselves jerkily up and down, uttering a shrill chirp, and finishing with a short song. The Grass-Finches depress the beak when dancing, and frequently sway from side to side; many of them also hold a long grass-stem in their beaks; some sing clearly, others almost inaudibly, uttering a weak sibilant song.

The Mannikins behave much like the Grass-Finches, but their tails are spread out fanwise, and they hop sideways, turning from right to left as they approach the hen; their songs are sometimes clear, but more frequently are a mere weak vibrant humming, with a few creaky notes, and a final prolonged reedy whistle. The Whydahs court hovering, rising and falling with loud beatings of the wings above the perched hen. The action of these birds reminds one forcibly of that of gnats sporting in a swarm; it is extremely graceful. The song, which is harsh and unpleasant, seems to be chiefly used as a war-cry. By its habits the little Ultramarine Finch (Hypochera) is undoubtedly a Whydah with short upper tail-coverts, and is, in my opinion, related to Vidua hypocherina. The typical Weavers, although belonging to two groups, separated by scientists under the subfamilies Ploceinæ and Viduinæ, have many peculiarities in common. They depend greatly upon their brilliant plumage, and the expansion of their crests, ruffs, and flank-plumes for attraction in their courtship; they nevertheless sing their harsh songs when making this display. The species of Pyromelæna, when singing, draw back the head, erect the feathers of the crown, nape, back, rump, upper tail-coverts, and flanks; indeed, all the feathers on the body seem to be partly erected, greatly adding to the apparent size and beauty of the birds. After the song, having the feathers still extended, they chase the hens with a curious mechanical buzzing flight, such as I have noticed in no other birds.

Among the Starling-like birds, I have been able to make very few observations; but I believe the Meadow-Starlings show off to their hens upon the wing, flying over, and singing to them. Thus the Red-breasted Marsh-bird (Leistes superciliosus), and the Military Troopials (Trupialis militaris and T. defilippii), are able to exhibit the gorgeous crimson of their under parts, which, when they crouch upon the earth, is almost completely hidden.

I have never kept pairs of any of the Crows; therefore cannot speak from experience of their courtship; but this is true also of many other groups. Parrots and Doves make friends with their mates by feeding and caressing them, but the different groups of Doves have various ways of showing off; the Columbidæ bowing very low, with erected expanded tail and drooped wings; then, lifting the head high, and throwing out the chest, they coo simultaneously. The Peristeridæ do much the same thing, the tail opening and shutting like a fan.

The Bar-shouldered Dove (Geopelia humeralis) at first bows to his hen, as already described; but, if she ignores his attentions, he turns his back upon her, raises his head high, spreads his tail downwards so that it sweeps the earth, runs forward with an angry little guttural sound, and looks back at her over his shoulder. If, after doing this about a dozen times, she still takes no notice, he rushes at her in a fury, and commences plucking feathers from her neck and back. The other species of Geopelia (Columbula picui and Chamæpelia passerina) show off in the usual manner; I have not seen them assume the second offended attitude adopted by G. humeralis.

I have never had a hen of the Cape Dove, and the cocks, when by themselves, are singularly apathetic; so that I have not been able to note the behaviour of this singular looking bird; but the Australian Green-winged Dove (Chalcophaps chrysochlora), the Bronze-winged Pigeon (Phaps chalcoptera), and the Australian Crested Pigeon (Ocyphaps lophotes) raise their wings over their backs in front of the erected and spread tail; as they bow, both tail and flight feathers open and shut, whilst with every action the birds utter a rapid grunting monosyllabic coo. The hen Bronze-wing often mounts the cock bird when pairing, and I supposed at first that this was owing to my male being rather old and afflicted with gouty toes; but my friend Mr. Seth-Smith tells me that he has seen his birds behave in the same manner.

Wells's Ground-Dove (Leptoptila wellsi) behaves exactly in the same way as the Peristeridæ, and pairs freely with the Martinican Dove, taking turns with it in sitting on the eggs, but up to July of this year without result, the eggs not being fertile.

The Bleeding-heart Pigeon (Phlogœnas luzonica) rarely bows to its hen, although I have seen it do so; it usually races after her at full speed, its head bobbing forwards at each step. As it nears her it stops, depresses its tail, throws out its breast, draws back its head, and utters a smothered coo, rocking backwards and forwards on its feet; it thus exhibits the beautiful deep crimson-and-rose patch on the breast to perfection. I have also seen it stop suddenly, quiver its wings, and utter a rapid "gu-gu-gu-gu-gu-gu." When the hen Bleeding-heart persistently evades its pursuer, he eventually loses his temper; and then a new feature is introduced into his wooing. As he still chases her, he claps his wings over his back, making a sharp noise like the loud crack of a whip; this seems greatly to alarm the hen. I have wondered whether a similar sound produced by our Goatsucker is intended to subdue its mate.

The Nicobar Pigeon (Calœnas nicobarica) is a singularly surly bird, and I have never seen him make any attempt to woo his mate. All she ever got from him was a savage blow from his powerful wing, or his almost equally powerful bill, accompanied by a deep grunt. He is a great awkward cowardly bird, more like a Guinea-fowl than a Pigeon; and, but for his brilliant colouring, I do not think many aviculturists would care to keep him.

The songs of birds are not only often overrated, but when represented in words are usually quite unrecognizable. When you come to think of it, there are very few consonants which can be whistled, and, although a singing bird can give some idea of a t sound, a ch, or a ph in his notes, such utterances as tell and spink are utterly beyond him. In writing down the song of a bird in words, if you wish to convey any idea of the notes to your readers, you should first whistle in imitation of the bird, and then so far as possible write down the notes.

The songs of the Thrushes are capable of endless variation. I doubt if there were ever two Song-Thrushes or two Blackbirds which whistled alike, and yet, as a rule, the songs of these birds, of the Robin, and even of that most accomplished bird, the Mocking-bird (Mimus polyglottus), are unmistakable. But if you hand-rear a Blackbird or Thrush, not permitting it to hear its wild song, its notes all go wrong, and either result in a miserable Gregorian chant, or something akin thereto, or to a noisy jangle of sound which is simply appalling. I once had a hand-reared Song-Thrush which had been brought up in a poultry-yard, and subsequently placed in a room where some Canaries were kept. The song was so noisy and penetrating that I gladly sold the bird to a publican, who was wild to secure it. The natural performance of the Song-Thrush is not brilliant, but cheerful and exhilarating; yet I have heard exceptionally gifted Thrushes more than once.

Unless you can place the young of any of the Thrushes where they can hear their natural song, it is a mistake to handrear them; my hand-reared Nightingales never sang a note. It is therefore evident that the songs of these birds are not instinctive; they are not handed down from father to son as natural gifts, but are taught as children are taught. But this does not hold true of all birds, unless we believe, as some have asserted, that certain birds learn their parent's song while yet in the egg—a notion which to me seems absurd.

I have found that hand-reared Sky-Larks, however young they may be taken from the nest, sing the wild song perfectly, although they usually add parts of the songs of other birds which they may hear; and I am inclined to believe that the true song-birds, with the exception of the Mocking-bird and one or two others, rarely learn additional notes after they have become adult. There are notable exceptions to this rule, inasmuch as an Alario Finch (Alario alario) which I possessed for some years entirely forgot its melodious little song, and adopted the far less pleasing song of a Norwich Canary; and my Brazilian Hangnest (Icterus jamacaii) has copied to perfection the almost metallic sharp cry of a Blue-bearded Jay (Cyanocorax cyanopogon), in addition to his own far more pleasing notes.

Certainly the adult birds which are the best mimics, and are easily taught to talk and imitate the cries of various animals, of trumpets, jews'-harps, and the like, are not to be sought among gifted songsters, but among those whose natural cries are more or less harsh and unpleasing—such as the Parrots, Crows, and Starlings. The capacity of some of the Psittacidæ in this respect is practically unlimited. The late Mr. J. Abrahams had a Blue-fronted Amazon which I heard sing the whole of the words of two comic songs, and then whistle the tune of a third—a feat which, I suppose, has never been surpassed even by the best instructed Grey Parrot.

If it were possible—though, unhappily, it rarely is so—the best way to record the songs of birds would be unquestionably by musical notation. My friend Mr. Charles A. Witchell has done much in this direction, but he himself is constrained to admit "that there is no instrument which will automatically reproduce the different tones of birds, and that difference of tone or of timbre is generally more important than difference in musical pitch." For this reason I think it better for anyone who has a good ear to express the songs of birds as closely as he can in words; but, unless he really has a correct appreciation of sound, it is wiser to let the songs of birds severely alone.

As with the songs, so is it with the call-notes, notes of alarm, or defiance; these are wrongly rendered in hundreds of cases, and are frequently transposed, the note of anger being spoken of as the call-note, or the reverse. These are points that need very careful testing before they are put on record; and an observant aviculturist, who has not only watched birds in their native haunts, but has had them constantly before him in moderately large aviaries, is in a better position to form a correct judgment of the meanings of these notes than the collector.

The colouring of the soft parts in birds can only be studied when the latter are either living or recently dead. The skins in collections give no idea of them, and stuffed specimens, based upon incorrect information, sometimes entirely misrepresent them. Here the aviculturist can greatly assist the cabinet naturalist or the taxidermist, if these men will accept his statements in good faith; and in this respect my late colleague, Dr. R. Bowdler Sharpe, showed a right scientific feeling, in that he was always glad of any facts I could give him respecting the colouring of the beaks, irides, naked face-patches, and feet of species in my possession.

To cite a few instances in which errors have occurred may perhaps be useful. The Spectacled Thrush (Trochalopterum canorum) is so called because the eye is enclosed in a lozenge-shaped ashy-grey naked patch; yet this very characteristic feature is omitted from descriptions taken from the dried skins. The colouring of the iris in the common Jay has been systematically stated to be brown in young birds, but blue in adults; whereas the young birds have the iris blue, and the adults vinous brown. The soft parts of Icterus jamacaii (the Brazilian Hang-nest) are thus described: "Bill black, at the base plumbeous; feet black"; the iris not being noted. In life the bill is very dark slate-coloured, the lower mandible with the basal half ashy whitish; the iris very pale amber (or transparent primrose); the eye enclosed in an elongate subpyriform bluish-ashy naked patch; feet black. The soft parts of Acridotheres cristatellus are not quite correctly described, for this Crested Mynah is said to have the "bill pale yellow, with the base rose-coloured; feet orange-red; iris orange-yellow"; whereas in life the bill is bone whitish, pinkish at the base; feet ochre-yellow; iris orange. The soft parts of the Passerine Dove have been variously described, and it seems possible that there may be more than one species confounded under the name of Chamæpelia passerina. It is admitted that local forms showing more or less vinous colouring in the plumage exist, and if these differ markedly in the colouring of the soft parts they should, in my opinion, bear different names. Baird describes the northern form as having the bill and feet yellow, the former tipped with brown; Dresser says, "beak purplish black, iris bright red, legs flesh-coloured"; whereas the specimens which I have had alive had the bill orange, tipped with dark brown; iris purple, with pale ochreous eyelid; feet pink. In the Bleeding-heart Pigeon the irides have been described as dark brown, but when closely examined they are seen to be plum-coloured.

But it is not only in the soft parts that errors have crept into scientific descriptions and illustrations. The feathers on the head are often taken liberties with. In vol. xiii. of the 'British Museum Catalogue of Birds' the artist has represented the head of the Crested Mynah (Acridotheres cristatellus) with a crest from the middle of the bill to the nape, whereas in life the crest begins at the outer third of the bill, and terminates on the forehead; the feathers of the crown lie perfectly flat and smooth, nor can they be erected.^[2] In like manner the plate in vol. xii. illustrating the species of Paroaria is entirely incorrect, P. cucullata being the only Crested Grey Cardinal, all the others, in life, having perfectly smooth heads; moreover, the Crested Cardinal has its crest far more erect in life than in the illustration. I always think it a mistake for taxidermists, when preparing skins of crested birds, to fasten back and dry the crests in an unnatural position; it must be most misleading for artists, if not for describers. I have always insisted upon having the crests of my dead birds left standing as in life.

Touching young plumages and seasonal changes of plumage, with the manner in which these changes are contrived, the aviculturist is in a position to be of great use to the systematist. The young of quite common birds are often wanting, even in the best collections of skins, or are imperfectly represented. Thus I found that my late colleague, Dr. Sharpe, was glad to have young examples of the Saffron-Finch (Sycalis flaveola), with the ages attached; whilst very young skins of the Zebra-Finch (Tæniopygia castanotis) were in great request, the description of the young having been necessarily omitted from the Catalogue for lack of material. I believe that young examples of the Gouldian Finch (Poëphila mirabilis) in the green and grey plumage are still in request, and I hope that any who are successful in breeding this species, and who lose the young before their change into the adult plumage, will send them promptly to the National Collection.^[3]

As regards the acquirement of the adult plumage, some tropical birds are very precocious, but others extremely dilatory. Some of the little Ploceid Finches (such as Amadina fasciata and Tæniopygia castanotis) are in full adult plumage and ready to breed when about six to eight weeks old; thus examples of the former, which left the nest in September, were breeding in October; and it is not uncommon for Zebra Finches (T. castanotis) to build and lay when eight weeks old. Mr. Meade-Waldo, speaking of the Chinese Quail (Excalphatoria sinensis), says: "They were hatched on July 23rd, and were in adult plumage by August 27th."

On the other hand, the Satin Bower-bird is known to be very slow in acquiring its adult plumage; the late Mr. Abrahams used to put the date of change at three years of age, but the Director of the Zoological Gardens, Melbourne, Mr. A.A.C. Le Souëf, says that he "caged a number (at least a dozen), ... and it was only after the expiration of nearly eight years they began to change colour. I think four or five birds put on the beautiful blue-black plumage, and in a year or two died off. It is therefore evident that the birds only come to their full plumage in old age, and that accounts for the fact that in a flock of, say, one hundred birds, which we often used to see at Gembrook some years ago, there would be only a very few, not half a dozen, black ones among them."^[4]

It is well known that in many species the flocks which assemble for migratory or other purposes consist wholly of birds of one sex. Two or three years ago (and again this year) the bird-market was flooded with Pekin Nightingales (Liothrix lutea), of which I bought three dozen examples in various conditions of plumage, hoping to secure plenty of males of that charming songster; but all proved to be hens. It is also well known that old hen birds often assume male plumage towards the end of their lives,^[5] owing to disease of the ovary, and it is probable that birds in captivity (which certainly live longer, when properly treated, than birds at liberty) are more subject to that disease than when they are free. This would be a more probable solution of the late assumption of the blue-black plumage by Mr. Souëf's birds than the conclusion that the Satin Bower-bird only assumed its black clothes to die in. The wedding garments of birds are believed to be assumed for the subjugation of the hens, and birds do not wait until they are old before they begin to breed.

There is no doubt that albinism in birds is due to constitutional weakness, and is a frequent result of close inbreeding. If a pair of Sparrows (Passer domesticus) takes up its quarters in one part of a building, or in the roof of an isolated cottage, the young, inbreeding for successive generations, are pretty certain to throw individuals with more or less white in the plumage. The White Dove (popularly known as "White Java") is known to be merely the albino form of the Collared Turtle (Turtur risorius), and Mr. Abrahams assured me that it could always be produced by close inbreeding from the common type. It is probable that inbreeding first produced the pied Java Sparrows, from which the Chinese, by careful selection, evolved the white variety of that species. White in the plumage of birds is frequently due to old age, and increases year by year. A Chaffinch which I had for about fifteen years acquired quite white eyelids before its death, and a Cordon-bleu (Estrilda phœnicotis), now in my possession, began to acquire a white wing-speculum some three or four years ago; this has now become a large white patch. A pied Chaffinch, which I once caught in the garden, became much whiter at the two succeeding moults; and a pied Blackbird sent to me a year or more ago showed an increase of white after its autumn moult; both were delicate birds, and did not live long, so that I conclude they were probably inbred.

Of the assumption of the breeding plumage by certain birds without a moult, or with only a moult of such feathers as have to be replaced by decorative plumes and crests, I have written recently in the 'Avicultural Magazine,' vol. viii. pp. 132–5; therefore, I need not enter into that matter again here. Those interested in the dispute as to the possibility of a change in the colour of feathers can easily refer to this paper, and to one which I published in 'The Ibis' for 1897.

It has always seemed to me a strange thing that ornithology, probably the most advanced study in the biological series, should in one respect be at fault, namely, in the reliance which the systematic student places upon the sexing of his specimens by collectors, and his objections to any other method but dissection for ascertaining the sex. Where would the aviculturist be, if (apart from colour differences) he were unable to be sure whether a bird was male or female?

In collections one frequently sees skins which have been incorrectly sexed by collectors—the young of Cyanospiza ciris, showing the commencement of the scarlet under surface of the cock bird on the flanks, yet labelled female; or, perchance, such easily sexed birds as the common Linnet, with no indication as to whether they are males or females. If one points out differences in form of beak, width of skull, length of wing, width of wing-markings, or other (apparently trifling, but actually trenchant) characters, one is met by the assertion that these are all variable, and therefore unreliable. I discovered a reason for the supposed unreliability of the sexual characters some years since when comparing my male, female, and young of Sialia sialis (the American Blue-bird) with the beautiful series in the British Museum collection. The males of Thrushes are rather longer and more slenderly built birds than the females; they have narrower skulls, and longer and more slender bills; but, when I compared my young cock Blue-bird (which had acquired its adult plumage) with its parents, I discovered that it was shorter than its mother, had quite as broad a skull, and a distinctly broader and shorter bill. I found that this young bird was uniform in every respect with all males of the same length in the Museum series, and that this apparently variable character was therefore due to the fact that Sialia acquires its adult colouring before it has lost all its structurally youthful characters, the bill of the nestling bird not having been perfectly modified into the long slender form of the fully matured male.

I have written so many short articles upon the sexing of birds by external characters, that I feel it would be superfluous to go again over the whole ground. I will therefore confine myself to a few general suggestions, which may be useful as guides to the student of this subject. There maybe exceptions to the general rules, because my studies have necessarily been confined to a comparatively small number of species; and, moreover, there are still many families of birds which I have not examined; so that, even if my distinctions should prove constant to all members of a family, much yet remains to be done.

So far as I have had an opportunity of testing sexual characters, I believe that among flying birds, in which the male is dominant, the primaries of the male are longer than those of the female, or, at any rate, the wing from its base to the end of the longest primary shows greater length.

In the Thrushes (Turdidæ), I believe it will be found to be the rule that the entire body is longer in the male, the skull and bill longer and narrower. In the Liotriges the adult males are rather larger than the females, with their bills slightly, but very slightly, broader. In the Bulbuls the same differences occur, but they are more pronounced. In the Tanagers I believe the culmen of the upper mandible in adult cock birds is generally more arched, but the difference is not very marked, and young males in full colour show it less clearly than old birds. However, the sexes of Tanagers generally differ somewhat in colour, even the Superb Tanager (Calliste fastuosa) not being difficult to sex when fully adult. The sexes of Finches differ as regards the form of their beaks according to their habits, so that no general rule can be laid down for them; the males are usually larger than the females, and have longer wings. The Crows (Corvidæ) have broader and stronger bills in the males than in the females. The so-called Piping Crows (Gymnorhina) have longer and more slender bills in the males. The males of Larks are broader in chest, are altogether larger, and have longer wings than the females. The Parrots (according to the late Mr. Abrahams) have a much more rounded blunter infero-posterior angle to the lower jaw in the males than in the females. The Doves are very difficult to sex where colour-characters are wanting, but the males usually, if not always, show a more prominent forehead than the females.

If there were no truth in these differences, it would be impossible for the aviculturist, when dealing with species in which the sexes showed no colour differences, to select pairs for breeding purposes. If we take the common Java Sparrow (Padda oryzivora) as an example, I may state that at various times I have picked out pairs repeatedly, both for myself and others, for breeding purposes, and hitherto have never been wrong in my selection; or, if we take the Crested Cardinal (Paroaria cucullata)—from five specimens which I purchased some years ago, I selected a pair, and placed them together in an aviary. Presently the cock began to sing and show off to the hen, a nest was built, and one or two eggs dropped on the floor, proving conclusively that my pairing had been correct.

It has been objected that, allowing the sexual differences in the beaks of birds to be reliable when the creatures are alive, so much shrinkage takes place after death, that the character of the beak is modified so as to be untrustworthy for comparison. This, however, is an error based upon supposition rather than experiment. The beak, being the horny sheath of a bony structure, changes its character very little; indeed, if it did it would hardly form a suitable basis for generic or specific diagnosis.

Touching the construction of nests by birds, a great deal of poetic nonsense has been written. Most nests are pleasing objects, and some are extremely artistic; but it is not true that the most elaborate nest is entirely beyond imitation by a skilled workman; indeed, I am satisfied that a Chinese artist would be able to fashion an excellent copy of the nest of a Long-tailed Tit (that most beautiful of English types) in a tithe of the time occupied by the birds. As for the cup-shaped nest, it is formed in the most rough-and-ready fashion, and its beauty is dependent largely upon the materials used in its construction. If you watch a Finch building in a bush, as I have frequently done in my aviaries, you will be astonished to discover how easily it is managed. The hen bird picks up a long piece of hay or a grassstalk by the end, flies into the bush, and hops round from twig to twig in circular fashion, so that the stem is left entangled in a circle or half-circle; then off she goes for a second; until at length there is a pile of tangled material somewhat depressed in the centre. Now she sits down, and begins turning round, tucking in ends; then off she goes again for a scrap of moss or wool, and tucks that in; then perhaps there is a little strengthening of the outer walls by tucking in ends, twisting an end of wool round a twig, and so on. The soft inner lining is formed in the most mechanical manner; the bird collects mouthful after mouthful of wool, cow-hair, feathers, or any soft material, and carries it into the nest, until the cup appears almost full; then she sits down, scratches with her feet, and turns round and round until she has moulded it with her body into a compact felted inner cup. The addition of a few horse-hairs generally completes the little structure.^[6] All cup-shaped nests are formed much in the same manner, though some birds use sticks, thorny twigs, straws, or roots, where others use grasses; some strengthen the outer nest with muddy roots, with clay, or cow-dung, where others use wool, vegetable fibre, and spiders' web. The lining also varies, the Song-Thrush using mud or cow-dung, and moulding it with her body until it resembles the inside of half a cocoanut-shell.

There is far more art in the construction of a domed nest, and it necessarily takes the architects much longer; it is all built up bit by bit, of more or less mixed materials, if it be the nest of a Wren or a Tit; and the outside is sometimes decorated with fragments of lichen attached by means of cobweb. It is this which renders the Long-tailed Tit's nest so beautiful an object. If a soft lining is required, soft feathers are frequently used, and the bird entering the cavity, twisting and turning, pushes up with its head, and pokes the ends of the shafts into the walls.

The Weaving Finches (Ploceidæ), excepting when they build in holes or other convenient receptacles, have to work both industriously and cleverly before their home is ready; but only in a few instances is the labour confined to one sex, the nest being generally constructed by the males in the Fire-Weavers (Pyromelæna), and in the Yellow and Black African Weavers (Hyphantornis); by the females in the Whydahs (Vidua and allies); by both sexes in Ploceus, although the female only comes in at the finish to assist the male in forming the cup for the reception of the eggs.

It is certainly a most interesting sight to notice how a Hyphantornis, with beak and claw, commences his snail-shell-shaped nest, attaching it to the wirework over the top of an aviary. He is so quick in passing an end of grass through the wire, holding it with one claw, then with his beak pulling it back through the next mesh. But the true Weavers are marvellous; they are born architects, and delight in their work as many an old lady does in knitting.

It is instructive to watch Waxbills (Estrilda and allies) at work—the female inside the nest, the male outside—alternately passing the end of a grass-stem backwards and forwards, until a strongly-laced, but semitransparent, globe is formed, with entrance-hole in front (but not invariably with depressed entrance-shaft leading to it). And, speaking of this netting instinct in Weavers, reminds me that among the cup-builders there is a group of very clever Weavers (Spermophila), whose nests are suspended between twigs, and formed of fine tough fibre. I supplied my birds with fine willow-fibre, and the delicate lacelike nests, of which unfortunately I did not preserve a specimen, were beautiful little works of art.

How does a bird learn to build the nest which is characteristic of its species, its genus, or its family? Charles Dixon asserted that the young bird remembered and copied the nest in which it was reared—that its gifts were not instinctive. On the other hand, I assert that a bird, by seeing the inside of its parents' nest, could not understand how it was formed inside, much less outside; and that experiment proves conclusively that it does not necessarily form its nest on the pattern of that in which it was reared.

Charles Dixon speaks of a Chaffinch introduced into New Zealand which built a long tapering nest, somewhat resembling that of one of the native birds of that country, as evidence of the truth of his statement. Seebohm, however, in his 'British Birds,' records the case of a Chaffinch which built a very similar nest in England, with no such pattern to guide it. On the other hand, birds which have been bred for centuries in square boxes fixed in cages, and therefore have had no opportunity, for numerous generations, of inspecting their ancestral homes, when turned loose in an aviary furnished with shrubs, frequently build in the latter nests of the same type as those formed by their wild forefathers. It would be difficult to say when the Japanese first originated the little Bengalee (a true Guinea-pig among birds), of which one ancestor—possibly the only one—was in all probability the Striated Finch (Munia striata). It has been bred in small cages, perhaps for a thousand years. When it is turned into an aviary, and elects to build in a bush, it forms the typical domed nest, with entrance-hole in front, characteristic of all the Mannikins. The Canary, on the other hand, invariably builds the cup-shaped nest characteristic of true Finches. I have had these nests built in my aviaries year after year by different birds, invariably reared in the ordinary London breeding-cage.

If we deny inherited memory to birds, how are we to account for the natural fear which hand-reared birds always exhibit at the sight of a Cat; they can have no personal experience of danger connected with the presence of that creature, yet all alike are terrified at the sight of it. The Canary, which has been so coddled by man that it has become stupid, and has been so constantly accustomed to the sight of Cats for many generations, that its natural dread of them has been blunted, is perhaps the only type of bird which frequently loses its life through the loss of the instinctive fear which might have saved it.

It is generally believed that because in certain groups of Weavers the male bird is accustomed to build the nest, therefore the female is unable to do so. This I disproved in the case of a pair of Pyromelœna franciscana, which I purchased about the year 1885, the hen of which built and nearly completed a nest, but unhappily died (as did the cock bird) before it was finished. In like manner it is supposed that the hens of the true Finches only are able to build, but in 1895 I bred Goldfinches in one of my aviaries. The first nest was entirely built by the hen, but the second nest was built entirely by the cock, before the young of the first family were ready to fly. The hen then went and inspected the second home, and, finding it comfortable, took no further notice of her young family, which were reared by their father whilst their mother incubated a second clutch of eggs. It is possible that this may be a not unusual plan among wild Finches, and it would be interesting if owners of large aviaries would look into it carefully.

Touching these Goldfinches, there was another point worthy of note in disproof of Charles Dixon's belief. Although they were wild-caught birds, they built their nests on the floor of a converted travelling Canary-cage hung upon the wires at the back of the aviary, not in a bush or on a branch, as they might have done. I have noticed the same changed habit in the case of the Grey Singing Finch (Serinus leucopygius). The Hartz travelling-cage is prepared by removing the perches, food-trough, and water-pot, putting in a solid floor, and pulling out two of the short uprights from one end to leave a small entrance-hole; and it struck me that the Finches may have preferred this easily defended position for their nests to the exposure of bush or branch; otherwise there seems no explanation for their change of habit. Birds undoubtedly think and reflect, or they would often be in a bad way. No doubt many of the marvellously protected nests formed by tropical birds are the result of the experimental and reflecting thoughts of the architects through many successive generations.

At the commencement of this article I spoke of the improvement of the intellect in birds when hand-reared, due to their constant association with man. This is frequently shown in the remarkable manner in which they engage naturally in games. I have had both a Pied Wagtail and a Canary (hand-reared), which, without teaching, correctly played the game of "Hide-and-seek," hiding up when we were out of the room, and, on our return, taking no notice of our calls until we had discovered the lost one, when it immediately called out like a child, and ran or flew to meet us. Our Wagtail also played a game somewhat resembling "Touch," as follows:—Three or four persons seated themselves at different parts of the dining-room table, and then the cage-door was opened. The Wagtail flew to the middle of the table, and glanced from one person to the other; then one pointed a finger. Immediately the Wagtail rushed excitedly across, and pecked the outstretched finger; then turned, and watched for some other person to do the same. Thus it rushed from one to another until it was tired of the fun, when it returned to its cage to rest. My hand-reared Jay is as playful as a puppy, and doubtless, if instructed by an experienced showman, might have been taught many tricks; but I never care to see any bird do strange things unless it does them for its own pleasure.

The notes uttered by my Wagtail would have puzzled as well as astonished a student of wild birds, so many and varied were they. The tone was changed so as clearly to express glee, anger, expostulation, pleading, fear; they were all call-notes of a kind, but most of them I never heard from a wild Wagtail. The song was very sweet and varied, more like that of the Swallow than of any other British bird.

The nidification of many foreign birds being imperfectly known, it is useful for the aviculturist not only to watch the behaviour of birds nesting in aviaries, but to save and blow infertile, addled, or deserted eggs, carefully marking them with the name of the species, and the date at which they were laid. It is true that the eggs of many imported birds are white, and differ chiefly in size, proportional dimensions, polish, &c, as, for instance, those of the Waxbills, Mannikins, Grass Finches, typical Weavers (Ploceus, but not Pyromelæna); the whole of the Doves and Parrots; yet to those who do not know them, they are of scientific interest, as representing part of the life-history of the species.

 

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1. A.T. Campbell's 'Nests and Eggs of Australian Birds,' p, 192, footnote.
2. Such errors are unavoidable when the skins of crested birds are not left as in life, but are strapped down by the taxidermist.
3. When I last saw the Museum series, the young plumage was unrepresented, but possibly examples may have been since received.
4. A.J. Campbell, 'Nests and Eggs of Australian Birds,' p. 192, footnote.
5. I had a remarkable instance of this in the case of a Rosa's Parrakeet (Palæornis rosa), which was so persecuted by her own child—a powerful young hen—that I had to cage her up separately. Two years later she assumed full male plumage, and a few months afterwards died. When opened the ovary was found to have almost entirely disappeared, the only remains being two twisted knots on the right side, almost simulating small testes.
6. The Chaffinch, however, frequently sticks bits of lichen all over the outside walls of her nest.