To quote the language of one of the ablest and most liberal-minded of our theologians:—“Science discloses the method of the World, Religion its cause, and there is no conflict between them, except when either forgets its ignorance of what the other alone can know.”

The next point to be noticed is the comparative abundance, in comparison with the rest of our Avifauna, of Rails, Ducks, and Cormorants. The first-named group contains in addition to Notornis and its allied form, Porphyrio, four, if not five, species of Ocydromus, three of Rallus, two of Ortygometra, and the diminutive Ocydromine representative in the Chatham Islands. Of Ducks, New Zealand possesses 11 species, belonging to ten genera, this number being far in excess of the proportion of Anseres to the general number of birds in other countries of similar extent. Of these Ducks, seven species are endemic, two of them (Nesonetta and Mergus) being confined to the small area of the Auckland Islands. Of Shags or Cormorants, including two at present doubtful forms, there are no less than fourteen species, of which eight, if not nine, are endemic, so that New Zealand in this respect takes the palm against all competitors. Some of the species, too, are of singular beauty, whereas in all other parts of the world the members of this family are noted for their plain faces and sombre plumage.

Seeing that New Zealand is so rich in Cormorants, it is indeed remarkable that there is no indigenous species of Plotus, a form so characteristic of Australia on the one hand and South America on the other. I have already recorded the occurrence of Plotus novœ hollandiœ as a straggler, which serves only to accentuate the inexplicable fact of its not being a native.

The entire absence of Woodpeckers might have been expected, as these birds do not extend beyond Celebes, never having been met with in the Moluccas or in Polynesia, New Guinea, or Australia. But it is difficult to account for the non-appearance of Swifts and Swallows, except as occasional visitants from Australia.

On the other hand, the Parrots are well represented. Besides the very typical Stringops habroptilus, already mentioned, we have seven species belonging to the genera Platycercus and Nestor, all of which are peculiar to New Zealand and her satellites.

As compared with the Avifauna of Australia, the paucity of species is particularly noticeable in the following well-distributed families, namely, Sylviidœ, Campephagidas, Muscicapidœ, Alcedinidœ, Columbidœ, and Tetraonidœ.

The families belonging exclusively to New Zealand are five in number—the Turnagridœ, Xenicidœ, Nestoridœ, Stringopidœ, and Apterygidœ—and, as already indicated, possibly a sixth represented by the remarkable genus Glaucopis. The great development of the Procellariidœ, or Family of Petrels, is a feature which New Zealand shares in common with Australia and Southern Polynesia. The South Pacific is the great nursery, so to speak, of this extensive Family, and no less than 33 species have, from time to time, been recorded on the New-Zealand coasts or from the surrounding seas. These include nearly all the known species of Albatros, and a number of oceanic birds of considerable interest, although as a rule not conspicuous for their beauty. Some of these have a range extending over both hemispheres; others are confined to apparently small tracts of ocean; while others again are migratory within certain degrees of latitude and longitude. Altogether they comprise a well-defined group of Birds (raised now to the dignity of an Order, under the name of Tubinares), whose economic and domestic history, owing to their pelagic and semi-nocturnal habits, has not yet been fully investigated or recorded.

red tailed tropic bird & great frigate bird The occasional capture in New Zealand of such tropical forms as Phaethon rubricauda and Tachypetes aquila, although interesting occurrences per se, cannot be regarded, in any strict sense, as a feature in the Avifauna.

Of Meliphagine birds New Zealand possesses a fair number in the genera Prosthemadera, Anthornis, Pogonornis, and, in a lesser degree, in Zosterops and the brush-tongued Nestor, all of which are endemic; but the honey-eating genera of Australia, such as Ptilotis, Meliphaga, and Tropidorhynchus, are entirely absent. Acanthochœra carunculata has occurred in a wild state, but only as an extremely rare straggler from the Eucalyptus-brushes of its native country.

Among the Limicolœ there are several species which touch at New Zealand in their seasonal migrations to and from the higher latitudes of the Eastern Hemisphere, or make this country their winter residence. Dr. Otto Finsch, as far back as 1867, in the Notes appended to his German translation of my ‘Essay on the Ornithology of New Zealand,’ expressed his surprise that such species as Strepsilas interpres, Totanus incanus, and Tringa canutus had not been recorded among these seasonal migrants. Since that time all of these, as well as Phalaropus fulicarius, Numenius cyanopus, and Tringa acuminata, have been added to the list. The two most remarkable instances, however, of this class are, on the one hand, the occasional occurrence of the Eastern Golden Plover (Charadrius fulvus), whose range extends over Australia, New Guinea, the islands of the Indian Archipelago, and Polynesia, and northwards to its breeding-grounds in Siberia and Kamtschatka, and, on the other, the regular autumnal migration of the Bar-tailed Godwit (Limosa novæ zealandiæ), which goes northwards to breed in the high latitudes of Eastern Asia. To my mind, in the whole romance of natural history there is nothing to be compared with this seasonal migration of the Godwit. This bird is the Eastern representative of the European Limosa lapponica, to which it bears a close resemblance; and, like that species, it has a very extensive geographical range. Both of them are migratory in their respective hemispheres; and while the other species breeds in, the high Northern latitudes of Europe, and returns in winter to North-west and East Africa, our bird spends a portion of the year in Siberia, and visits, in the course of its migration, the islands of the Indian Archipelago, Polynesia, Australia, and New Zealand! Towards the end of March, or beginning of April, large flocks may be seen at the far North taking their departure from our country. Rising from the beach in a long line and with much clamour, they form into a broad semicircle, and mounting high in the air, take a course due north: sometimes they rise in a confused manner, and, after circling about at a considerable height in the air, return to the beach to reform, as it were, their ranks, and then make a fresh start on their distant pilgrimage. After foreign travels and adventures which the pen of Audubon alone could do justice to, the flocks begin to reappear at the north during the first week of November, and then rapidly disperse along the coast.

This subject of the seasonal migration of certain birds is a very wide one and full of interest. There is probably nothing in the whole field of ornithological research more remarkable than this traditional habit, acquired no doubt by experience accumulated through countless generations. The same unerring instinct which guides the Ground-Lark to her nest under some particular tussock in the midst of a wilderness, miles in extent, of exactly similar tussock, or which enables the sea-bird to single out her own eggs from among the thousands clustered together on the bare rock or sandy beach, likewise guides the movements of the migrant when the time comes round for its annual pilgrimage.

We have in New Zealand two species of Cuckoo belonging to different genera—both migratory and both parasitic. One of these (the Long-tailed Cuckoo), which is a native of the Society Islands, visits this country in the summer and breeds with us, entrusting the task of rearing its young to a little Warbler not larger than an English Wren. It arrives, year after year, during the second week of October, and leaves us again before the end of February—this migratory habit, persevered in through long generations, having become a necessary part of its natural existence. In the whole range of ornithological biography, there is perhaps nothing more marvellous than this punctual annual migration across some fifteen hundred miles of ocean. The other species, known as the Shining Cuckoo, visits us from Australia, performing its journey of a thousand miles with the same wonderful precision as to dates of arrival and departure, my register showing only a maximum variation of five days during a continuous period of ten years. Curiously enough, this mild little caterpillar-hunter entrusts the rearing of its young to the same bird that performs that friendly office for its predatory congener four times its size. But apart from these regular summer visitants, with which most colonists are familiar, we have numerous instances of eccentric and casual migration which are indeed very curious. The history of the little Zosterops, or Blight-bird, is a case in point. This migrant crossed Cook's Strait, for the first time within the memory of man, in the winter of 1856, coming over in numerous flocks, as if to explore the country; then retired for two years, and reappeared in greater numbers than before in the winter of 1858, since which time it has been a permanent resident in the North Island, breeding in every district, and becoming more plentiful every year. This migration was no doubt induced, in the first instance, by a scarcity of some particular food-supply in the South Island, which must have occurred again two years later. The exceptional feature, however, in this case is, that after the second migration the natural impulse to return home had lost its influence.

In Australia we have several records of non-migratory birds performing a kind of exodus from their own part of the country, swarming into some distant region, where they have remained for five or even ten years, and then disappearing as suddenly as they had come. Take, for example, the beautiful little Warbling Parrakeet (Melopsittacus undulatus), which, prior to 1838, was so rare in the southern parts of Australia that only a single example had been sent to Europe, but arrived in that year in countless multitudes. Or take the case of the Australian Moorhen (Tribonyx ventralis). ‘This bird, although not endowed with any extraordinary powers of flight, acting under some mysterious influence, left its home in the remote interior and visited South Australia in 1840, coming in such countless myriads that whole fields of corn were trodden down and destroyed in a single night, and the streets and gardens of Adelaide were alive with them. But the casual occurrence with us of migratory species from Australia is even more singular, because it seems impossible to assign any definite cause. In March, 1851, a flight of the Australian Tree-Swallow appeared at Taupata, near Cape Farewell; ten years later they were observed again at Wakapuaka, near Nelson, and a specimen obtained; and after a further lapse of fully twenty years another flight—from which a specimen is now in my possession—appeared for several days in succession in the outskirts of Blenheim. More recently, the Press Association announced the appearance of “Swifts” at the White Cliffs, near Taranaki, and on receiving the only specimen that was shot, I found it to be the true Australian Swift (Cypselus pacificus), a bird common enough on the Hunter but migratory northward, and believed by most naturalists to be identical with the species inhabiting China and Amoorland. The two instances of the occurrence in New Zealand, after an interval of twenty years, of the Australian Wattle-bird (Acanthocera carunculata), and more recently, in both North and South Islands, of the well-known Australian Roller (Eurystomus pacificus), are cases in point; and other instances might be given of the mysterious, overpowering impulse, under the influence of which certain birds, without any apparent motive, perform almost incredible aerial journeys without a break of any kind.

Another remarkable feature in the New-Zealand Avifauna is the inherent tendency to albinism

In the body of the present work will be found carefully recorded instances of albinism, more or less pronounced, in the following species, viz.:—Glaucopis wilsoni, G. cinerea, Heteralocha acutirostris, Creadion carunculatus, Myiomoira macrocephala, Anthus novæ zealandiæ, Anthornis melanura, Prosthemadera novæ zealandiæ, Platycercus novæ zealandiæ, P. auriceps, Nestor meridionalis, Spiloglauæ novæ zealandiæ, Sceloglaux albifacies, Circus gouldi, Carpophaga novæ zealandiæ, Hæmatopus longirostris, H. unicolor, Himantopus novæ zealandiæ, Limosa novæ zealandiæ, Larus dominicanus, Ocydromus earli, O. australis, Porphyrio melanonotus, Ardea sacra, Phalacrocoraæ novæ hollandiæ, Ossifraga gigantea, Anas superciliosa, A. chlorotis, A. gibberifrons, Podiceps rufipectus, Apteryx australis, A. mantelli, and A. oweni.

To the above list Mr. Kirk has recently added Myiomoira toitoi, having described (‘Ibis,’ 1888, p. 42) a specimen in the possession of Mr. J. H. Drew of Wanganui, in which the only indication of the normal colouring is a small patch of faint grey on one of the primaries, the whole of the remaining plumage being pure white.

In my account of Anthus novæ zealandiæ I have stated (at p. 64) that albinos, more or less pure, are of common occurrence. In the above-cited communication Mr. Kirk says of this species:—” While travelling through the bush on the east coast of the Wellington province, I came on a Maori plantation, and was shown by one of the natives a Ground-Lark exhibiting a tendency both to albinism and melanism. The following is a description, jotted down in my pocket-book:—Top of head, and down as far as a line through the eye, dull black; the whole of the body and wings, with the exception of the two outer primaries, were a delicate creamy white; the outer primaries retained the normal greyish-brown colour. The outside tail-feathers, which in an ordinary specimen would be white, were in this case jet-black. This bird, which was one of the most curious freaks of nature I ever saw, had been tamed, would come when called and allow itself to be picked up and examined, as though conscious of deserving attention on account of its extraordinary and fantastic dress. I endeavoured to effect a purchase, but without success, the Maoris appearing to set great store by their pet.”

Strange to say, there is the same tendency to albinism in the imported birds. Albino Sparrows are far more common than they are in their native country, and even the Sky-Lark (Alauda arvensis) not unfrequently exchanges its sober dress for a yellowish-white one. In illustration of this I brought to England two specimens of the latter, one of which I presented to the British Museum, the other to the Natural-History Museum at Cambridge.

Among the Parrots I have recorded some beautiful crimson and yellow varieties, and in the case of Platyoercus novæ zealandiæ a single instance of cyanism. But the only New-Zealand birds in which I have ever detected any tendency whatever towards melanism, and then only in a slight degree, were Anthornis melanura and Miro albifrons.

Many travellers in New Zealand have remarked on the notable absence of bird-life, especially in the woods; and at certain seasons of the year this is indeed very noticeable. But, as fully explained in my history of the Wood-Pigeon at page 232, the relative abundance or scarcity of birds is entirely regulated by the food-supply, which, in turn, is governed by the seasons. At all times, however, in winter and summer alike, the New-Zealand woods, whether alive with birds or not, possess an indescribable charm owing to their evergreen character. In my several accounts of their feathered inhabitants I have, as the reader will perceive, never lost an opportunity of paying my tribute to the luxuriant beauty of these woods; but I have always felt that it was quite impossible to do full justice to the subject

Mr. W. R. Ringland, of Belfast, who accompanied me through one of the northern forests, in the summer of 1884, thus graphically describes it in his ‘Notes of Travel’:—

“This bush scenery is indeed very wonderful. The enormous cabbage-trees, the gorgeous creepers clinging in a green network to the tall pines, the dense undergrowth of shrubs, the tree-ferns, the great kauris, and the exquisite tints of the whole mass of riotous vegetation are beautiful beyond description. Then the strange silence, unbroken even by the whir of a bird's wing, the unchanging sameness of the bush, that confuses you until you cannot tell how far you have travelled, the charred tree-trunks on either side of the road that have been burnt down to clear a passage, and the oppressive loneliness of it all, tell that you are far away from the beaten track of travel, and far into the heart of Maoriland.”

In the strictest sense of the term, New Zealand is without “song-birds”; but such species as the Tui, the Korimako, and the Piopio possess vocal powers of a very respectable kind, the compass and variety of their notes adding greatly to the charm of the New-Zealand woods. For example, the North-Island Thrush (Turnagra hectori) has many notes exactly resembling those of its English namesake. As fully explained at pp. 28, 29 this handsome species is rapidly dying out and will soon be but a memory of the past. But with the disappearance of this native Thrush, the English songster is fast becoming established in the country, frequenting the outskirts of the bush in the neighbourhood of European settlements and supplying to the loyal colonist yet another link of attachment to “dear old England.”

Setting aside, however, their claim to the highest order of song, the birds of New Zealand do not fail, especially in the early morning, to make their native woods echo with delightful music, “each one giving out his own notes without any regard for the others, the score having evidently been written for the whole, since the innumerable strains make one divine harmony.” In the midst of this melody of song, the harsh cry of the Kaka calling to its fellows will sometimes for a moment break the spell, but the performers, heedless of the discordant note and with bursting throats, continue their morning concert, till, as if by common consent, they cease altogether and disperse in quest of their daily food.

Another feature not to be lost sight of in considering the present condition of the New-Zealand Avifauna is the rapid way in which it is being affected, and in some instances effaced, by the introduction of the so-called useful and ornamental birds from other parts of the world. The conditions of existence are very favourable to the establishment and increase of many of the imported forms, and, as a consequence, the indigenous species are being displaced and supplanted by them to a very alarming degree. The colony of New Zealand, like every other new country, has been, from time to time, possessed as it were by a rage for acclimatization; and the zeal for the introduction of novelties has not always been tempered by the judgment which comes of experience. The Author must himself plead guilty to having been accessory to the importation of the House-Sparrow in 1865, having in that year, on behalf of the Wanganui Acclimatization Society, advertised in the London newspapers offering a reward of £100 for 100 pairs of House-Sparrows delivered alive in the colony. The advertisement and the importation alike succeeded; and at the present day myriads of these birds in all parts of the country attest the fact, and in the grain-season especially they elicit even from their strongest partisans the admission that they are not an “unmixed blessing.” While, however, admitting myself that the “Sparrow nuisance” does exist in rather an aggravated form, I do claim on behalf of this bird full credit for its strictly insectivorous habits at a certain season of the year, and I have never lost an opportunity, in spite of the odium, of putting in a plea for the poor persecuted Passer domesticus

As with all questions of this kind, there is much to be said for and against the Sparrow, and numerous experiments have been made by friends and foes for the purpose of demonstrating the actual truth of the case. The following newspaper record contains the result of one of these experiments, and, so far as my observation goes, the weight of evidence is invariably in favour of the bird:—“A hundred and eighteen Sparrows have been offered upon the altars of science. As was the case with the Pagan sacrifices, their entrails have been carefully inspected, in order to furnish guidance to the inquirers. But it has not been in search of the cabalistic information to be derived from quaint contortion, or the credited, though impossible, absence of the heart, or some other vital organ, that the sacrificial knife has been bared. The contents of the stomachs of the victims have been examined, tabulated, recorded. Three culprits alone, out of this hecatomb of the favourites of Cytherea, were proved, by the unsparing search, guilty of having lived for the past four-and-twenty hours upon grain. In fact, there were three thieves out of the 118; all the other victims had worked, more or less, for their living. Beetles, and grubs, and flies, and larvæ of all obnoxious kinds had been their diet. In 75 of the birds, infants of all ages, from the callow fledgling to the little Pecksy and Flapsy that could just twitter along the ground, hardly any but insect remains were detected. What would the starved and industrious pioncers who have reared their wonderful temple and city by the Great Salt Lake have given for the aid of an army of English Sparrows against that greater and more formidable host of grasshoppers which thrice all but annihilated the settlement?”

To give the other side of the argument, and to show that the prejudice against the Sparrow and its consequent punishment is not confined to New Zealand, I may quote the following newspaper account of its status in Australia:—“Rome once owed its salvation to a Goose, but it has been reserved for the Sparrow in these degenerate modern days to threaten a flourishing young State with serious loss, if not, as the farmers assert, absolute ruin. Rabbits have for some years played an important part in directing legislation in some of the Australasian Colonies, and now in South Australia the Sparrow is becoming a power in the land, and calls for all the machinery of special Acts of Parliament to keep it within bounds. The bird, which only a few years ago such efforts were made to acclimatize in Australia, and whose first arrival was hailed with greater enthusiasm than would now be displayed on the landing of a Bend Or, a Duchess, or a prize merino, is now doomed to extermination—if that can possibly be achieved. So rapidly have the few pairs which were introduced a few years ago multiplied under the congenial skies and amid the luxuriant vegetation of the Australian Colonies, where there are few or none of the checks on their increase which exist in the Old Country, that the agriculturists complain of the serious injury done by them to their wheat and fruit crops, and have called upon the Government to devise some means of ensuring their destruction…… Its work is done on a scale disheartening to the cultivator, and under conditions he cannot control, for the seed is taken out of the ground, the fruit-bud off the tree, the sprouting vegetable as fast as it grows, and the fruit ere it is ripe, and therefore before it can be housed and saved. Neither apricots, cherries, figs, apples, grapes, peaches, plums, pears, nectarines, loquats, olives, wheat, barley, peas, cabbages, cauliflowers, or seeds or fruits of any kind, are spared by its omnivorous bill; and all means of defence tried against its depredations, whether scarecrows, traps, netting, shooting, or poisoning, are declared to be insufficient to cope with the enemy. It remains to be seen whether the reward offered by the Government for the heads and eggs of these destructive little birds will result in any diminution in their numbers.”

In his last-named work, Mr. Wallace divides all known islands into two classes, “Continental” and “Oceanic.” The former are always more varied in their geological formation—containing both ancient and recent stratified rucks—are rarely remote from a continent, and always contain some land Mammalia, also Amphibia and representatives of the other classes of animals in considerable variety. The “Oceanic” islands are usually far removed from continents and are always separated from them by very deep seas, are entirely without land Mammalia or Amphibia, but are generally well stocked with birds and insects and with some reptiles. Now New Zealand, which is undoubtedly “Continental” in its geological formation, also in the existence of the submerged bank already described connecting it in ancient times with North Australia and New Guinea, is as decidedly “Oceanic” in its zoological character, except as regards its wingless birds and the remarkable tuatara lizard (Sphenodon punctatum), which is said to constitute per se a distinct order of Reptilia of extreme antiquity. Mr. Wallace therefore terms New Zealand and the Celebes, where the conditions are somewhat similar, “Anomalous islands;” but Ancient continental may be perhaps a more convenient term.

As already explained, at the time of the supposed land-connection to the North-west, the Marsupial fauna could not have reached the eastern land now forming part of Australia; but it seems very probable that, at this early period, tropical Australia was tenanted by some Struthious kind of bird, perhaps volant in its character, which had reached this land, by way of New Guinea, through some ancient continental extension. If this theory, so well propounded by Mr. Wallace, is the true one, then the Cassowaries of New Guinea, the Emus of Australia, the extinct Dromornis of Queensland, and the Moas and Kiwis of New Zealand are doubtless the moditied descendants of this ancestral type. “The total absence (or extreme scarcity) of mammals in New Zealand obliges us to place its union with North Australia and New Guinea at a very remote epoch. We must either go back to a time when Australia itself had not yet received the ancestral forms of its present marsupials and monotremes, or we must suppose that the portion of Australia with which New Zealand was connected was then itself isolated from the mainland, and was thus without a mammalian population… But we must on any supposition place the union very far back, to account for the total want of identity between the winged birds of New Zealand and those peculiar to Australia, and a similar want of accordance in the lizards, the freshwater fishes, and the more important insect groups of the two countries. From what we know of the long geological duration of the generic types of these groups we must certainly go back to the earlier portion of the Tertiary period at least in order that there should be such a complete disseverance as exists between the characteristic animals of the two countries, and we must further suppose that, since their separation, there has been no subsequent union or sufficiently near approach to allow of any important inter-migration, even of winged birds, between them. It seems probable, therefore, that the Bampton shoal west of New Caledonia, and Lord Howe's Island further south, formed the western limits of that extensive land in which the great wingless birds and other isolated members of the New-Zealand fauna were developed. Whether this early land extended eastward to the Chatham Islands and southward to the Macquaries we have no means of ascertaining; but as the intervening sea appears to be not more than 1500 fathoms deep, it is quite possible that such an amount of subsidence may have occurred. It is possible, too, that there may have been an extension northward to the Kermadec Islands, and even further to the Tonga and Fiji Islands, though this is hardly probable, or we should find more community between their productions and those of New Zealand. A southern extension towards the Antarctic continent at a somewhat later period seems more probable, as affording an easy passage for the numerous species of South American and Antarctic plants and also for the identical and closely allied freshwater fishes of these countries. The subsequent breaking up of this extensive land into a number of separate islands—in which the distinct species of Moa and Kiwi were developed—their union at a later period, and the final submergence of all but the existing islands, is a pure hypothesis, which seems necessary to explain the occurrence of so many species of these birds in a small area, but of which we have no independent proof”

‘Island Life,’ p. 454.

In a preceding section I have already mentioned that, as a rule, the species of Dinornis which, in former times, inhabited the North Island were different in character from their contemporaries in the South Island, although the two areas of land are only separated by a strait scarcely eighteen miles across in its narrowest part. The same feature is maintained to the present day in the existing Avifauna, clearly showing that each island has a biological history of its own. Thus the Saddle-back (Creadion carunculatus) of the North is represented in the South by C. cinereus, a closely-allied species, but differing in the colour of its plumage; Nth Is thrushTurnagra hectori (now almost extinct) is represented by T. crassirostris, a species that will soon follow suit, although still plentiful in certain localities; the Weka (Ocydromus earli) is represented by several other closely-related species (O. australis, O. fuscus, and O. brachypterus) so closely resembling the northern bird both in appearance and habits that they are called “Woodhens” by the settlers of both islands and by them, as well as by the natives, are generally regarded as identical; the Popokatea (Clitonyx albicapilla) is represented by another species (C. ochrocephala) differing in colour, but so closely allied to it that the Maoris apply the same name to both; the Toutouwai (Miro australis), to which precisely the same remark applies, is represented by M. albifrons, and Glaucopis wilsoni by G. cinerea, distinguishable only by the colour of its ornamental wattles. Another case in point is furnished by the two representative species of Apteryx, the North Island bird being characterized by a different structure of plumage to that of the well-known Apteryx australis inhabiting the South Island. Till of late years it was believed that Apteryx oweni, which differs entirely from both of these species in the grey colour and mottled appearance of its plumage, was confined to the colder districts of the South Island; but in 1876 I communicated to the Wellington Philosophical Society the discovery of this bird near the summit of the Tararua mountains on the north side of Cook's Strait, where it was found frequenting the stunted vegetation immediately below the snow-line

Trans. N.-Z. Instit. vol. viii. pp. 193–194.

Analogous cases of representative species in more or less widely separated areas are of frequent occurrence in other parts of the world. “The cause of this” (writes Mr. Wallace) “is very easy to understand. We have already shown that there is a large amount of local variation in a considerable number of species, and we may be sure that were it not for the constant intermingling and intercrossing of the individuals inhabiting adjacent localities this tendency to local variation would soon form distinct races. But as soon as the area is divided into two portions, the intercrossing is stopped, and the usual result is that two closely allied races, classed as representative species, become formed. Such pairs of allied species on the two sides of a continent, or in two detached areas, are very numerous; and their existence is only explicable on the supposition that they are descendants of a parent form which once occupied an area comprising that of both of them,—that this area then became discontinuous,—and, lastly, that, as a consequence of the discontinuity, the two sections of the parent species became segregated into distinct races or even species.”

In his ‘Geographical Distribution of Animals’ Mr. Wallace treats New Zealand and her satellites as forming a subregion of Australia. The Australian, or “great insular region of the earth,” is divided by him into four subregions, distinguished as the Austro-Malayan, Australian, Polynesian, and New Zealand. The last-named subregion is made to include Norfolk Island, Phillip and the Nepean Isles, Lord Howe's Island and the Kermadec Isles on the north, the Chatham Islands on the east, the Auckland, Macquarie, Emerald, Campbell, Antipodes, and Bounty Islands on the south and south-east.

Other prominent writers on the subject have claimed for New Zealand full recognition as a separate biological province, quite distinct from Australia and every other region of the earth, My own study of the subject having brought me to the same conclusion, I propose to examine here, very briefly, the grounds upon which Mr. Wallace links New Zealand to Australia as contiguous sections of one biological region. He admits, of course, that there is a “wonderful amount of speciality,” but he contends that “the affinities of the fauna, whenever they can be traced, are with Australia or Polynesia.”

If we take Mr. Wallace's own table of the geographical distribution we find, on a careful analysis, that out of twenty-eight families stated to be common to Australia and New Zealand, three are included in error, namely Sittidæ, Dicæidæ, and Pandionidæ, thus reducing the number to twenty-five. Of these, fifteen are admitted by him to be cosmopolitan, and may therefore be discharged from the present inquiry. Of the remaining ten, four belong to the Old World, four to the Oriental, Ethiopian, Austro-Malayan, and Polynesian regions respectively, and one highly specialized family, the Spheniscidæ, to the south temperate regions, leaving thus only one family, the Tit mouseParidæ, as restricted in its range to the two countries. This family is represented in New Zealand by a single genus, Certhiparus, about the true position of which there is considerable doubt, and this genus again is represented by a single species, so that, as regards the mere distribution of families, the argument altogether fails. Let us now examine the far more important question of identical or representative genera and species in the two countries, for this after all is the true test of a common origin. Of the twelve genera of Australian birds which he treats as belonging equally to New Zealand, it may be remarked that two (namely Graucalus and Acanthochœra), each of them represented by a single species, have only occurred in New Zealand as accidental stragglers, at very long intervals; that Tribonyx, as already explained at p. xiv, has never actually occurred in a wild state; and that Orthonyx and Hieracidea have, on further investigation of their characters, been replaced by two endemic genera, Clitonyx and Harpa. Of the remaining seven, two alone (Gerygone and Sphenœacus) are characteristic of Australia, the others ranging over a great part of the southern hemisphere; thus, Platycercus is spread over New Guinea and Polynesia, as well as Australia, Rhipidura extends to India, and Zosterops through Polynesia and the Malay Archipelago to India and Africa. Of the five species mentioned by Mr. Wallace as being identical in Australia and New Zealand, it may be mentioned that three (Acanthochæra carunculata, Graucalus melanops, and Hirundo nigricans) are among our rarest stragglers from abroad, and that the Shining Cuckoo (Chrysococcyx lucidus) is an annual migrant to and from Australia: thus leaving only Zosterops cœrulescens to be accounted for, and this species has been sufficiently treated of already.

Mr. Wallace's strongest point is the Family Meliphagidæ, which is a very typical and well-distributed Australian group. But accepting, as I think we must do, his theory of the introduction of the ancestral types into New Zealand by way of tropical Australia and New Guinea, it is easy to account for the presence of this peculiar form in both countries, inasmuch as the Meliphagidae have representatives as far north as the Sandwich Islands, whilst other members of the group are spread through the Austro-Malayan subregion, finding their extreme western limit in the Celebes. Supposing that the ancient type reached New Zealand by the north-western route, it then resolves itself into a mere question of time and “descent with modification.”

Dr. Otto Finsch, who has written several interesting papers on New-Zealand Ornithology, appears to me to exaggerate very much the importance of this feature, for he accepts it as a proof of “far more intimate connection with Australia than one would suppose from the geographical position of the two countries.” He is unable, however, to account for the absence of true Trichoglossi in New Zealand, seeing that this group is so strongly developed in the temperate parts of Australia.

It is a point of some significance that the Meliphagine genera in New Zealand are not very closely related to those of Australia, except in the case of Pogonornis, which approximates somewhat to Ptilotis, a decidedly subtropical genus. Apart from the true Honey-eaters, the only genera that Mr. Wallace specially refers to as related to peculiar Australian ones are Miro and Myiomoira (allied to Petrœca), Ocydromus (allied to Eulabeornis), and Hymenolœmus (allied to Malacorhynchus). It seems to me, therefore, that he has not succeeded in establishing a co-ordinate relation between the avifaunae of these so-called subregions of Australia.

It is worthy of remark also that, with the exception of the highly developed Meliphagidae, comprising four very distinct genera (and numbering altogether only five species), none of the New-Zealand families contain more than two genera, presenting a marked difference in this respect to the numerous subordinate groups among the birds of Australia.

Seeing that the Shining Cuckoo (Chrysococcyx lucidus) is met with in New Guinea, and probably further west, that it is likewise found in tropical Australia, and that it comes to us from the north, or north-west–for it always makes its appearance first at the extreme north–it is easy to understand that the migratory impulse has been inherited from time immemorial, and the more so as the closely-allied species (C, plagosus) is also a summer visitant to the temperate and southern portions of Australia. But it is very difficult to imagine why the Long-tailed Cuckoo (Eudynamis taitensis), which hibernates in the warm islands of the Pacific–the Friendly, Society, Marquesas, Fiji, and Samoa groups–ranging over more than 40° of longitude, should make its annual pilgrimage across 1500 miles of ocean to New Zealand

Mr. Wallace says, in his account of the Chatham Islands (‘Island Life,’ p. 454):—“It is stated that the Zosterops differs from that of New Zealand, and is also a migrant; and it is therefore believed to come every year from Australia, passing over New Zealand, a distance of nearly 1700 miles!” But this is evidently a lapsus calami, the bird intended being the Chrysococcyx. Prof. Hutton stated (Trans. N.-Z. Instit. vol. v. p. 225) that this happened in the case of C. plagosus; but I have shown elsewhere that he was wrong in his identification of the species, the Shining Cuckoo (C. lucidus) which annually visits the Chatham Islands being identical with the New-Zealand bird. Chrysococcyx plagosus, distinguished by its narrower bill, has never been met with in New Zealand, and it would be strange indeed if this Australian species had occurred in the Chatham Islands to the eastward.

The Waders are, for the most part, cosmopolitan, and are therefore of little account when estimating the geographical relations of the avifauna.

I have endeavoured to make the technical part of the work as exhaustive and exact as possible. After the diagnostic characters of each species (rendered, according to the usual custom, in Latin), I have given full descriptions of both sexes, with their seasonal changes of plumage (if any), followed by an account of the young, commencing with the nestling, or fledgling, and noting the various adolescent states of plumage in the progress of the bird towards maturity. Under the head of ‘Varieties,’ I have been careful to record every appreciable departure from the normal character that has come under my notice during an acquaintance with this peculiar Ornis extending over the best part of my life.

The measurements of each bird described are given in inches and decimals. In taking the extreme length my rule has always been to measure from the tip of the bill, following its curvature (if any) to the end of the tail. The advantage of this plan is that by deducting the measurements of the culmen and the tail, which are given separately, the exact length of the body may be ascertained. The same rule has been followed in regard to the claws wherever measurements are given.

In order to make the descriptions intelligible to the ordinary reader, some knowledge is essential of the names usually applied to the various parts of a bird and to the feathers which cover them. To supply an index to the descriptive terms commonly employed throughout the present work, it may be useful to reproduce here, on a slightly reduced scale, the diagram given in my ‘Manual of the Birds of New Zealand,’ the outline selected for the purpose being that of one of our commonest species.