Page:EB1911 - Volume 03.djvu/996

to those instances in which the members of families, genera and species are mentioned. The families are those which are enumerated in Garow’s classification. The numbers of genera and species of birds are, of course, a matter of personal inclination. If we take a moderate computation the number of recent species may be taken at 10,000-11,000.^[1] Dr R. B. Sharpe increases their number to about 15,000 in the New Hand-List of Birds, published by the British Museum. In the first two volumes fossil birds, occasionally based upon a fragmentary bone only, are also included.

(A) Austrogaea, the Australian region in the wider sense, with the Papuan, Australian and New Zealand subregions, including also Polynesia. We may here quote Newton (Encyclopaedia Britannica, 9th ed., “Birds,” p. 738) on the remarkable differences between this region and the rest of the Old World:—“The prevalent zoological features of any Region are of two kinds—negative and positive. It is therefore just as much the business of the zoogeographer, who wishes to arrive at the truth, to ascertain what groups of animals are wanting in any particular locality (altogether independently of its extent) as to determine those which are forthcoming there. Of course, in the former case it would be absurd to regard as a physical feature of any great value the absence from a district of groups which do not occur except in its immediate neighbourhood; but when we find that certain groups, though abounding in some part of the vicinity, either suddenly cease from appearing or appear only in very reduced numbers, and occasionally in abnormal forms, the fact obviously has an important bearing. Now, mere geographical considerations, taken from the situation and configuration of the islands of the so-called Indian or Malay Archipelago, would indicate that they extended in an unbroken series from the shores of the Strait of Malacca to the southern coast of New Guinea, which confronts that of north Australia in Torres Strait, or even farther to the eastward. Indeed, the very name Australasia, often applied to this part of the world, would induce the belief that all the countless islands, be they large or small—and some of them are among the largest on the globe—were but a southern prolongation of the mainland of Asia. But so far from this being the case a very definite barrier is interposed. A strait, some 15 m. or so in width, and separating the two fertile but otherwise insignificant islands of Bali and Lombok, makes such a frontier as can hardly be shown to exist elsewhere. The former of these two islands belongs to the Indian Region, the latter to the Australian, and between them there is absolutely no true transition—that is, no species are common to both which cannot be easily accounted for by the various accidents and migrations that in the course of time must have tended to mingle the productions of islands so close to one another. The faunas of the two are as absolutely distinct as those of South America and Africa, and it is only because they are separated by a narrow strait instead of the broad Atlantic that they have become so slightly connected by the interchange of a few species and genera.

“Now, first, of the forms of birds which are prevalent throughout the Indian Region, but are entirely wanting in the Australian, we have at once the bulbuls (Ixidae), very characteristic of most parts of Africa and Asia, including the sub-group Phyllornithinae, which is peculiar to the Indian Region; the widely-spread families of barbets (Megalaeminae) and vultures (Vulturidae); and the pheasants (Phasianidae), which attain so great a development in various parts of the Asiatic continent and islands that there must their home be regarded as fixed. Some naturalists would add the finches (Fringillidae), rightly if we assume that the Ploceidae or weavers constitute a separate family. Then, of forms which are but weakly represented, we have the otherwise abundant thrushes (Turdidae), and, above all, the woodpeckers (Picidae), of which only very few species, out of 400, just cross the boundary and occur in Lombok, Celebes or the Moluccas, but are unknown elsewhere in the region.”

But the Australian region is also remarkable for its ornithic singularity. All the existing Ratitae (with the exception of the ostriches of Africa and South America, belonging to the genera Struthio and Rhea, and comprising at most but five species) are found in Austrogaea and nowhere else. Of the Passeres the honey-suckers (Meliphagidae) are most characteristic, and, abounding in genera and species, extend to almost every part of the region, yet only one species of Ptilotis oversteps its limits, crossing the sea from Lombok to Bali. Other peculiar families are much more confined. But the positive characteristics of the region as a whole are not its peculiar forms alone; there are at least four families which, being feebly represented elsewhere, here attain the maximum of development. Such are the thick-headed shrikes (Pachycephalidae), the caterpillar-eaters (Campephagidae), the flower-peckers (Dicaeidae), and the swallow-flycatchers (Artamidae). Besides these, three or perhaps four groups, though widely distributed throughout the world, arrive in the Australian region at their culmination, presenting an abundance of most varied forms. These are the weaver-birds (Ploceidae), and the moreporks (Podargidae), but especially the kingfishers (Alcedinidae) and the pigeons (Columbidae), the species belonging to the two last obtaining in this region a degree of prominence and beauty which is elsewhere unequalled.

The boundaries of the subregions are not well defined.

Fig. 22.—Extinct Phillip-Island Parrot (Nestor productus).
(From specimen in the British Museum. Reduced.)

The New Zealand Subregion, considered by Professors Newton and Huxley and various other zoogeographers as deserving the rank of a region, is, and to all appearance has long been, more isolated than any other portion of the globe. Besides the three larger islands numerous satellites belong to the subregion, as Lord Howe, Norfolk and Kermadec islands, with the Chatham, Auckland and Macquarie groups. The main affinities of the avifauna are, of course, Australian. The most extraordinary feature is unquestionably the former existence of the gigantic Dinornithes or moas (q.v.) and, another family of Ratitae, the weird-looking kiwis or Apteryges, which are totally unlike any other existing birds. Of other peculiar genera it will suffice to mention only the more remarkable. Rallidae present the very noteworthy woodhens, Ocydromus, and the takahe, Notornis, which is almost extinct. The widely-spread plovers, Charadriidae, have two not less singular generic developments, Thinornis, and the extraordinary wrybill, Anarhynchus. There is an owl, type of the genus Sceloglaux. Of parrots, Stringops, the kakapo or owl-parrot, is certainly peculiar, while Nestor constitutes a peculiar subfamily of the brush-tongued parrots or Trichoglossidae. Xenicus and Acanthositta form a little family of truly mesomyodean Passeres Clamatores. Of the Meliphagidae the genera Prosthemadera, Pogonornis and Anthornis are peculiar. The starlings, Sturnidae, are represented by Callaeas, Creadion and the very abnormal Heterolocha. The gallinaceous birds are represented by a quail, Coturnix novae zealandiae, now exterminated. A large flightless goose, Cnemiornis, allied to the Australian Cereopsis, and the gigantic rapacious Harpagornis, have died out recently, with the moas. In all, there is a wonderful amount of specialization, though perhaps in a very straight line from generalized forms; but the affinity to Australian or Polynesian types is in many cases clearly traceable, and it cannot be supposed but that these last are of cognate origin with those of New Zealand. A very long period of isolation must have been required to produce the differences so manifestly to be observed, but a few forms seem at rare intervals to have immigrated, and this immigration would appear to be kept up to our own day, as shown by the instance of Zosterops lateralis, which is said to have lately made its first appearance, and to have established itself in the country, as well as by the fact of two cuckoos,

---

1. The following old-fashioned rough computation may serve as an indication of the relative size of the orders and suborders of recent birds:—
   
   

   Ratitae Colymbiformes Sphenisciformes Procellariiformes  Ciconiiformes Anseriformes Falconiformes Tinamiformes Galliformes

   20 20 15 90 150 150 360 40 370

   Gruiformes   Charadriiformes   Cuculiformes   Coraciiformes   Passeres Clamatores   Passeres Oscines Total about

   250 650 600 1600 1000 5000 ——— 10,300

   (incl. Columbae 350) (incl. Psittaci 400) (incl. Trochili and Pici)  species