A FOREST IN BORNEO, WITH CHARACTERISTIC MAMMALIA.
A FOREST IN BORNEO, WITH CHARACTERISTIC MAMMALIA.
Plate VIII. Scene in Borneo with Characteristic Malayan Quadrupeds.—The Malayan fauna is so rich and peculiar that we devote two plates to illustrate it. We have here a group of mammalia, such as might be seen together in the vast forests of Borneo. In the foreground we have the beautiful deer-like Chevrotain (Tragulus javanicus). These are delicate little animals whose body is not larger than a rabbit's, thence often called "mouse-deer." They were formerly classed with the "musk-deer," owing to their similar tusk-like upper canines; but their anatomy shows them to form quite a distinct family, having more resemblance to the camels. On the branch above is the curious feather-tailed Tree-Shrew (Ptilocerus lowii), a small insectivorous animal altogether peculiar to Borneo. Above this is the strange little Tarsier (Tarsius spectrum), one of the lemurs confined to the Malay islands, but so distinct from all others as to constitute a separate family. The other small animals are the Flying Lemurs (Galæopithecus volans) formerly classed with the lemurs, but now considered to belong to the Insectivora. They have a very large expansion of the skin connecting the fore and hind limbs and tail, and are able to take long flights from one tree to another, and even to rise over obstacles in their course by the elevatory power of the tail-membrane. They feed chiefly on leaves, and have a very soft and beautifully marbled fur.
In the distance is the Malayan tapir (Tapirus indicus), a representative of a group of animals now confined to the larger Malay islands and tropical America, but which once ranged over the greater part of temperate Europe.
Birds.—Owing to several of the families consisting of very obscure and closely allied species, which have never been critically examined and compared by a competent ornithologist, the number of birds inhabiting this sub-region is uncertain. From the best available materials there appear to be somewhat less than 650 species of land-birds actually known, or excluding the Philippine Islands somewhat less than 600. The larger part of these are peculiar species, but mostly allied to those of Indo-China; 36 of the genera, as already stated, being common to these two sub-regions. There are, however, no less than 46 genera which are peculiarly or wholly Indo Malayan and, in many cases, have no close affinity with other Oriental groups. These peculiar genera are as follows:—Timalia,Malacopteron,Macronus,Napothera,Turdinus, andTrichixos—generaof Timaliidæ;Eupetes, a most remarkable form, perhaps allied toEnicurus, andCinclus;Rhabdornis(Certhiidæ) found only in the Philippines;Psaltria, a diminutive bird of doubtful affinities, provisionally classed among the tits (Paridæ);Setornis(Pycnonotidæ);Lalage(Campephagidæ) extending eastward to the Pacific Islands;Pycnosphrys,Philentoma(Muscicapidæ);Laniellus, a beautiful bird doubtfully classed with the shrikes (Laniidæ);PlatylophusandPityriasis, the latter a most anomalous form—perhaps a distinct family, at present classed with the jays, in Corvidæ;Prionochilus, a curious form classed with Dicæidæ;Erythrura(Ploceidæ), extending eastwards to the Fiji Islands;Gymnops,Calornis, (Sturnidæ);Eurylæmus,Corydon, andCalyptomena(Eurylæmidæ);Eucichla, the longest tailed and most elegantly marked of the Pittidæ;ReinwardtipicusandMiglyptes(Picidæ);PsilopogonandCalorhamphus, (Megalæmidæ);Rhinococcyx,Dasylophus,Lepidogrammus,Carpococcyx,Zanclostomus,Poliococcyx,Rhinortha, (Cuculidæ);Berenicornis,Caldo,Cranorhinus,Penelopides,Rhinoplax, (Bucerotidæ);Psittinus, (Psittacidæ);Ptilopus,Phapitreron, (Columbidæ);Rollulus, (Treronidæ);Machærhamphus, (Falconidæ). Many of these genera are abundant and wide-spread, while some of the most characteristic Himalayan genera, such asLarvivora,Garrulax,Hypsipetes,Pomatorhinus, andDendrocitta, are here represented by only a few species.
Among the groups that are characteristic of the Malayan sub-region, the Timaliidæ and Pycnonotidæ stand pre-eminent; the former represented chiefly by the generaTimalia,Malacopteron,Macronus, andTrichastoma, the latter byCriniger,Microscelis, and many forms ofPycnonotus. The Muscicapidæ, Dicruridæ, Campephagidæ, Ploceidæ, and Nectariniidæ are also well developed; as well as the Pittidæ, and the Eurylæmidæ, the limited number of species of the latter being compensated by a tolerable abundance of individuals. Among the Picariæ are many conspicuous groups; as, woodpeckers (Picidæ); barbets (Megalæmidæ); trogons (Trogonidæ); kingfishers (Alcedinidæ); and hornbills (Bucerotidæ); five families which are perhaps the most conspicuous in the whole fauna. Lastly come the pigeons(Columbidæ), and the pheasants (Phasianidæ), which are fairly represented by such fine genera asTreron,Ptilopus,Euplocamus, andArgusianus. A few forms whose affinities are Australian rather than Oriental, help to give a character to the ornithology, though none of them are numerous. The swallow-shrikes (Artamus); the wag-tail fly-catchers (Rhipidura); the green fruit-doves (Ptilopus); and the mound-makers (Megapodius), are the chief of these.
There are a few curious examples of remote geographical alliances that may be noted. First, we have a direct African connection inMachærhamphus, a genus of hawks, andBerenicornis, a genus of hornbills; the only close allies being, in the former case in South, and in the latter in West Africa. Then we have a curious Neotropical affinity, indicated byCarpococcyx, a large Bornean ground-cuckoo, whose nearest ally is the genusNeomorphusof South America; and by the lovely green-colouredCalyptomenawhich seems unmistakably allied to the orange-colouredRupicola, or "Cock of the rock," in general structure and in the remarkable form of crest, a resemblance which has been noticed by many writers.
In the preceding enumeration of Malayan genera several are included which extend into the Austro-Malay Islands, our object, at present, being to show the differences and relations of the two chief Oriental sub-regions.
Plate IX. A Malayan Forest with some of its peculiar Birds.—Our second illustration of the Malayan fauna is devoted to its bird-life; and for this purpose we place our scene in the Malay peninsula, where birds are perhaps more abundant and more interesting, than in any other part of the sub-region. Conspicuous in the foreground is the huge Rhinoceros Hornbill (Buceros rhinoceros), one of the most characteristic birds of the Malayan forests, the flapping of whose wings, as it violently beats the air to support its heavy body, may be heard a mile off. On the ground behind, is the Argus pheasant (Argusianus giganteus) whose beautifully ocellated wings have been the subject of a most interesting description in Mr. Darwin'sDescent of Man. The wing-feathers are here so enormouslydeveloped for display (as shown in our figure) that they become almost, if not quite, useless for their original purpose of flight; yet the colours are so sober, harmonizing completely with the surrounding vegetation, and the bird is so wary, that in the forests where it abounds an old hunter assured me he had never been able to see a specimen till it was caught in his snares. It is interesting to note, that during the display of the plumage the bird's head is concealed by the wings from a spectator in front, and, contrary to what usually obtains among pheasants, the head is entirely unadorned, having neither crest nor a particle of vivid colour,—a remarkable confirmation of Mr. Darwin's views, that gayly coloured plumes are developed in the male bird for the purpose of attractive display in the breeding season. The long-tailed bird on the right is one of the Drongo-shrikes (Bhringaremifer), whose long bare tail-feathers, with an oar-like web at the end, and blue-black glossy plumage, render it a very attractive object as it flies after its insect prey. On the left is another singular bird the great Broad-bill (Corydon sumatranus), with dull and sombre plumage, but with a beak more like that of a boat-bill than of a fruit-eating passerine bird. Over all, the white-handed Gibbon (Hylobates lar) swings and gambols among the topmost branches of the forest.
Reptiles and Amphibia.—These are not sufficiently known to be of much use for our present purpose. Most of the genera belong to the continental parts of the Oriental region, or have a wide range. Of snakesRhabdosoma,Typhlocalamus,Tetragonosoma,Acrochordus, andAtropos, are the most peculiar, and there are several peculiar genera of Homalopsidæ. Of Oriental genera,Cylindrophis,Xenopeltes,Calamaria,Hypsirhina,Psammodynastes,Gonyosoma,Tragops,Dipsas,Pareas,Python,Bungarus,Naja, andCallophisare abundant; as well asSimotes,Ablabes,Tropidonotus, andDendrophis, which are widely distributed. Among lizardsHydrosaurusandGeckoare common; there are many isolated groups of Scincidæ; whileDraco,Calotes, and many forms of Agamidæ, some of which are peculiar, abound.
Plate IX.
A MALAYAN FOREST, WITH ITS CHARACTERISTIC BIRDS.
A MALAYAN FOREST, WITH ITS CHARACTERISTIC BIRDS.
Among the Amphibia, toads and frogs of the generaMicrhyla,Kalophrynus,Ansonia, andPseudobufo, are peculiar: while the OrientalMegalophrys,Ixalus,Rhacophorus, andHyloranaare abundant and characteristic.
Fishes.—The fresh-water fishes of the Malay archipelago have been so well collected and examined by the Dutch naturalists, that they offer valuable indications of zoo-geographical affinity; and they particularly well exhibit the sharply defined limits of the region, a large number of Oriental and even Ethiopian genera extending eastward as far as Java and Borneo, but very rarely indeed sending a single species further east, to Celebes or the Moluccas. Thirteen families of fresh-water fishes are found in the Indo-Malay sub-region. Of these the Scienidæ and Symbranchidæ have mostly a wide range in the tropics. Ophiocephalidæ are exclusively Oriental, reaching Borneo and the Philippine islands. The Mastacembelidæ are also Oriental, but one species is found as far as Ceram. Of the Nandidæ, 3 genera range over the whole region. The Labyrinthici extend from Africa through the Oriental region to Amboyna, The single species constituting the family Luciocephalidæ is confined to Borneo and the small islands of Biliton and Banca. Of the extensive family Siluridæ 17 genera are Oriental and Malayan, and 11 are Malayan exclusively; and not one of these appears to pass beyond the limits of the sub-region. The Cyprinidæ offer an equally striking example, 23 genera ranging eastward to Java and Borneo and not one beyond; 14 of these being exclusively Malayan. It must be remembered that this is not from any want of knowledge of the countries farther east, as extensive collections have also been made in Celebes, the Moluccas, and Timor; so that the facts of distribution of fresh-water fishes come, most unexpectedly, to fortify that division of the archipelago into two primary regions, which was founded on a consideration of mammalia and birds only.
Insects.—Few countries in the world can present a richer and more varied series of insects than the Indo-Malay islands, and we can only here notice a few of their more striking peculiarities and more salient features.
The butterflies of this sub-region, according to the best estimate that can be formed, amount to about 650 described species, a number that will yet, no doubt, be very considerably increased. The genera which appear to be peculiar to it areErites(Satyridæ);Zeuxidia(Morphidæ);Amnosia,Xanthotænia, andTanæcia(Nymphalidæ). The groups which are most characteristic of the region, either from their abundance in individuals or species, or from their size and beauty, are—the rich dark-colouredEuplæa; the large semi-transparentHestia; the plain-colouredMycalesis, which replace our meadow-brown butterflies (Hipparchia); the curiousElymnias, which often closely resemble Euplæas; the large and handsomeThamantisandZeuxidia, which take the place of the giant Morphos of South America; theCethosia, of the brightest red, and marked with a curious zigzag pattern; the velvety and blue-glossedTerinos; the pale and delicately-streakedCyrestis; the thick-bodied and boldly colouredAdolias; the small wine-colouredTaxila; the fine blueAmblypodia; the beautifulThyca, elegantly marked underneath with red and yellow, which represent our common white butterflies and are almost equally abundant; the pale blueEronia, and the large red-tippedIphias. The genusPapiliois represented by a variety of fine groups; the largeOrnithoptera, with satiny yellow under-wings; the superb green-marked "brookeana;" the "paradoxa" group, often closely resembling the Euplæas that abound in the same district; the "paris" group richly dusted with golden-green specks; the "helenus" group with wide-spreading black and white wings; the black and crimson "polydorus" group; the "memnon" group, of the largest size and richly-varied colours; and the "eurypilus" group, elegantly banded or spotted with blue or green: all these are so abundant that some of them are met with in every walk, and are a constant delight to the naturalist who has the privilege of observing them in their native haunts.
The Coleoptera are far less prominent and require to be carefully sought after; but they then well repay the collector. As affording some measure of the productiveness of the tropics in insect life it will not be out of place to give a few notes of thenumber of species collected by myself in some of the best localities. At Singapore 300 species of Coleoptera were collected in 15 days, and in a month the number had increased to 520; of which 100 were Longicorns and 140 Rhyncophora. At Sarawak in Borneo I obtained 400 species in 15 days, and 600 in a month. In two months this number had increased to about 850, and in three months to 1,000 species. This was the most prolific spot I ever collected in, especially for Longicorns which formed about one-fifth of all the species of beetles. In the Aru Islands in one month, I obtained only 235 species of Coleoptera, and about 600 species of insects of all orders; and this may be taken as a fair average, in localities where no specially favourable conditions existed. On the average 40 to 60 species of Coleoptera would be a good day's collecting; 70 exceptionally good; while the largest number ever obtained in one day was 95, and the majority of these would be very minute insects. It must be remembered, however, that many very common species were passed over, yet had every species met with been collected, not much more than 100 species would ever have been obtained in one day's collecting of four or five hours. These details may afford an interesting standard of comparison for collectors in other parts of the world.
Of Cicindelidæ the most peculiarly Malayan form isTherates, found always on leaves in the forests in the same localities as the more widely spreadCollyris. Five genera of this family are Indo-Malayan.
The Carabidæ, though sufficiently plentiful, are mostly of small size, and not conspicuous in any way. But there is one striking exception in the purely Malayan genusMormolyce, the largest and most remarkable of the whole family. It is nocturnal, resting during the days on the under side of largeboletiin the virgin forest.PericallusandCatascopusare among the few genera which are at all brillantly coloured.
Buprestidæ are abundant, and very gay; the genusBelionotabeing perhaps one of the most conspicuous and characteristic. The giantCatoxanthais, however, the most peculiar, though comparatively scarce.ChrysochroaandChalcophoraare alsoabundant and characteristic. Out of the 41 Oriental genera 21 are Malayan, and 10 of these are not found in the other sub-regions.
In Lucanidæ the Malay islands are rich, 14 out of the 16 Oriental genera occurring there, and 3 being peculiar. There are many fine species ofOdontolabris, which may be considered the characteristic genus of the sub-region.
The Cetoniidæ are well represented by 16 genera and about 120 species. The generaMycteristes,Phædimus,Plectrone,Euremina,RhagopteryxandCentrognathusare peculiar, whileAgestrata,Chalcothea, andMacronotaare abundant and characteristic.
The Longicorns, as in all continental forest regions near the equator, are very abundant and in endlessly varied forms. No less than 55 genera containing about 200 species are peculiar to this sub-region, the Cerambycidæ being much the most numerous.Euryarthrum,Cœlosterna,Agelasta, andAstathesmay be considered as most characteristic; but to name the curious and interesting forms would be to give a list of half the genera. For the relations of the Longicorns of the Indo-Malay, and those of the Austro-Malay region, the reader is referred to the chapter on the distribution of insects in the succeeding part of this work.
Terrestrial Mollusca.—The Philippine islands are celebrated as being one of the richest parts of the world for land shells, about 400 species being known. The other islands of the sub-region are far less rich, not more than about 100 species having yet been described from the whole of them.HelixandBulimusboth abound in species in the Philippines, whereas the latter genus is very scarce in Borneo and Java. Ten genera of Helicidæ inhabit the sub-region;Pfeifferiais found in the Philippines and Moluccas, while the large genusCochlostylais almost peculiar to the Philippines. Of the Operculata there are representatives of 20 genera, of whichDermatomaandPupinellaare peculiar, whileRegistomaandCalliaextend to the Australian region.Cyclophorus,Leptopoma, andPupinaare perhaps the most characteristic genera.
The Zoological Relations of the Several Islands of the Indo-Malay Sub-region.
Although we have grouped the Philippine islands with the Indo-Malay sub-region, to which, as we shall see, they undoubtedly belong, yet most of the zoological characteristics we have just sketched out, apply more especially to the other groups of islands and the Malay peninsula. The Philippine islands stand, to Malaya proper, in the same relation that Madagascar does to Africa or the Antilles to South America; that is, they are remarkable for the absence of whole families and genera which everywhere characterise the remainder of the district. They are, in fact, truly insular, while the other islands are really continental in all the essential features of their natural history. Before, therefore, we can conveniently compare the separate islands of Malaya[12]with each other, we must first deal with the Philippine group, showing in what its speciality consists, and why it must be considered apart from the sub-region to which it belongs.
Mammals of the Philippine Islands.—The only mammalia recorded as inhabiting the Philippine Islands are the following:—
The foregoing list, although small, contains an assemblage of species which are wholly Oriental in character, and several of which (Tarsius,Galeopithecus,Tupaia) are characteristic and highly peculiar Malayan forms. At the same time these islands are completely separated from the rest of Malaya by the total absence ofSemnopithecus,Hylobates,Felis,Helarctos,Rhinoceros,Manis, and other groups constantly found in the great Indo-Malay islands and peninsula of Malacca. We find apparently two sets of animals: a more ancient series, represented by the deer,Galeopithecus, and squirrel, in which the species are distinct from any others; and a more recent series, represented byMacacus cynomolgus, andViverra tangalunga, identical with common Malayan animals. The former indicate the earliest period when these volcanic islands were connected with some part of the Malayan sub-region, and they show that this was not geologically remote, since no peculiar generic types have been preserved or differentiated. The latter may indicate either the termination of the period of union, or merely the effects of introduction by man. The reason why a larger number of mammalian forms were not introduced and established, was probably because the union was effected only with some small islands, and from these communicated to other parts of the archipelago; or it may well be that later subsidences extinguished some of the forms that had established themselves.
Birds of the Philippine Islands.—These have been carefully investigated by Viscount Walden, in a paper read before the Zoological Society of London in 1873, and we are thus furnished with ample information on the relations of this important portion of the fauna.
The total number of birds known to inhabit the Philippines is 219, of which 106 are peculiar. If, however, following our usual plan, we take only the land-birds, we find the numbers to be 159 species, of which 100 are peculiar; an unusually large proportion for a group of islands so comparatively near to various parts of the Oriental and Australian regions. The families of birds which are more especially characteristic of the Indo-Malay sub-region are about 28 in number, and examplesof all these are found in the Philippines except four, viz., Cinclidæ, Phyllornithidæ, Eurylæmidæ, and Podargidæ. The only Philippine families which are, otherwise, exclusively Austro-Malayan are, Cacatuidæ and Megapodiidæ. Yet although the birds are unmistakably Malayan, as a whole, there are, as in the mammalia (though in a less degree), marked deficiencies of most characteristic Malayan forms. Lord Walden gives a list of no less than 69 genera thus absent; but it will be sufficient here to mention such wide-spread and specially Indo-Malay groups as,—Eurylæmus,Nyctiornis,Arachnothera,Geocichla,Malacopteron,Timalia,Pomatorhinus,Phyllornis,Iora,Criniger,Enicurus,Chaptia,Tchitrea,Dendrocitta,Eulabes,Palæornis,Miglyptes,Tiga, andEuplocamus. These deficiencies plainly show the isolated character of the Philippine group, and imply that it has never formed a part of that Indo-Malayan extension of the continent which almost certainly existed when the peculiar Malayan fauna was developed; or that, if it has been so united, it has been subsequently submerged and broken up to such an extent, as to cause the extinction of many of the absent types.
It appears from Lord Walden's careful analysis, that 31 of the Philippine species occur in the Papuan sub-region, and 47 in Celebes; 69 occur also in India, and 75 in Java. This last fact is curious, since Java is the most remote of the Malayan islands, but it is found to arise almost wholly from the birds of that island being better known, since only one species,Xantholæma rosea, is confined to the Philippine Islands and Java.
The wading and swimming birds are mostly of wide-spread forms, only 6 out of the 60 species
being peculiar to the Philippine archipelago. Confining ourselves to the land-birds, and combining
several of the minutely subdivided genera of Lord Walden's paper so as to agree with the
arrangement adopted in this work, we find that there are 112 genera of land-birds represented in
the islands. Of these, 50 are either cosmopolitan, of wide range, or common to the Oriental and
Australian regions, and may be put aside as affording few indications of geographical affinity. Of
the remaining 62 no less than 40 are exclusivelyor
mainly Oriental, and most of them are genera which range widely over the region, only two
(PhilentomaandRollulus) being exclusively Malayan, and two others
(MegalurusandMalacocircus) more especially Indian or continental. Five other
genera, though having a wide range, are typically Palæarctic, and have reached the islands through
North China. They are,Monticola,Acrocephalus,Phylloscopus,Calliope, andPasser; the two first having extended their range southward into the
Moluccas. The peculiarly Australian genera are only 12, the majority being characteristic Papuan
and Moluccan forms; such as—Campephaga,Alcyone,Cacatua,Tanygnathus,Ptilopus,Janthænas, When we look at the position of the Philippine group, connected by the Bashee islands with
Formosa, by Palawan and the Sooloo archipelago with Borneo, and by the Tulour and other islets
with the Moluccas and Celebes, we have little difficulty in accounting for the peculiarities of
its bird fauna. The absence of a large number of Malayan groups would indicate that the actual
connection with Borneo, which seems necessary for the introduction of the Malay types of mammalia,
was not of long duration; while the large proportion of wide-spread continental genera of birds
would seem to imply that greater facilities hadonce existed for immigration from Southern China, perhaps by a land
connection through Formosa, at which time the ancestors of the peculiar forms of deer entered the
country. It may indeed be objected that our knowledge of these islands is far too imperfect to
arrive at any satisfactory conclusions as to their former history; but although many more species
no doubt remain to be discovered, experience shows that the broad characters of a fauna are always
determined by a series of collections made by different persons, at various localities, and at
different times, even when more imperfect than those of the Philippine birds really are. The
isolated position, and the volcanic structure of the group, would lead us to expect them to be
somewhat less productive than the Moluccas, close to the rich and varied Papuan district,—or
than Celebes, with its numerous indications of an extensive area and great antiquity; and taking
into account the excessive poverty of its mammalian fauna, which is certain to be pretty well
known, I am inclined to believe that no future discoveries will materially alter the character of
Philippine ornithology, as determined from the materials already at our command. Java.—Following the same plan as we have adopted in first discussing the
Philippine islands, and separating them from the body of the sub-region on account of special
peculiarities, we must next take Java, as possessing marked individuality, and as being to some
extent more isolated in its productions than the remaining great islands. Java is well supplied with indigenous mammalia, possessing as nearly as can be ascertained 55
genera and 90 species. None of these genera are peculiar, and only about 5 of the species,—3
quadrumana, a deer and a wild pig. So far then there is nothing remarkable in its fauna, but on
comparing it with that of the other great islands, viz., Borneo and Sumatra, and the Malay
peninsula, we find an unmistakable deficiency of characteristic forms, the same in kind as that we
have just commented on in the case of the Philippines, though much less in degree. First, taking
genera which are found in all three of the above-namedlocalities and which must therefore be held to be typical Malayan groups,
the following are absent from Java:Viverra,Gymnopus,Lutra,Helarctos,Tapirus,Elephas, andGymnura; while of thoseknownto occur in two, and which, owing to our imperfect knowledge, may very probably one day be
discovered in the third, the following are equally wanting:Simia,Siamanga,Hemigalea,Paguma,Rhinosciurus, andRhizomys. It may be said this is
only negative evidence, but in the case of Java it is much more, because this island is not only
the best known of any in the archipelago, but there is perhaps no portion of British India of
equal extent so well known. It is one of the oldest of the Dutch possessions and the seat of their
colonial government; good roads traverse it in every direction, and experienced naturalists have
been resident in various parts of it for years together, and have visited every mountain and every
forest, aided by bands of diligent native collectors. We should be almost as likely to find new
species of mammalia in Central Europe as in Java; and therefore the absence of such animals as the
Malay bear, the elephant, tapir, gymnura, and even less conspicuous forms, must be accepted as a
positive fact. In the other islands there are still vast tracts of forest in the hands of natives and utterly
unexplored, and any similar absence in their case will prove little; yet on making the same
comparison in the case of Borneo, the most peculiar and the least known of the other portions of
the sub-region, we find only 2 genera absent which are found in the three other divisions, and
only 3 which are found in two others. A fact to be noted also is, that the only genus found in
Java but not in other parts of the sub-region (Helictis) occurs again in North India; and
that some Javanspecies, asRhinoceros javanicus, andLepus kurgosaoccur
again in the Indo-Chinese sub-region, but not in the Malayan. Among the birds we meet with facts of a similar import; and though the absence of certain types
from Java is not quite so certain as among the mammalia, this is more than balanced by the
increased number of such deficiencies, so that if a fewshould be proved to be erroneous, the main result will remain
unaltered. Java possesses about 270 species of land birds, of which about 40 are peculiar to it. There
are, however, very few peculiar genera,Laniellus, a beautiful spotted shrike, being the
most distinct, whileCochoaandPsaltriaare perhaps not different from their Indian
allies. The island has however a marked individuality in two ways—in the absence of
characteristic Malayan types, and in the presence of a number of forms not yet found in any of the
other Malay islands, but having their nearest allies in various parts of the Indo-Chinese
sub-region. The following 16 genera are all found in Malacca, Sumatra, and Borneo, but are absent
from Java:Setornis,Temnurus,Dendrocitta,Corydon,Calyptomena,Venilia,Reinwardtipicus,Caloramphus,Rhinortha,Nyctiornis,Cranorhinus,Psittinus,Polyplectron,Argusianus,Euplocamus, andRollulus. The following 9 are known fromtwoof the above
localities, and will very probably be found in the third, but are absent from, and not likely to
occur in, Java:Trichixos,Eupetes,Melanochlora,Chaptia,Pityriasis,Lyncornis,Carpococcyx,Poliococcyx, andRhinoplax.
We have thus 25 typically Malayan genera which are not known to occur in Java. The following genera, on the other hand, do not occur in any of the Malayan sub-divisions
except Java, and they all occur again, or under closely allied forms, in the Indo-Chinese
sub-region;Brachypteryx(allied species in Himalayas);Zoothera(allied species in
Aracan);Notodela(allied species in Pegu);Pnoëpyga(allied species in Himalayas);Allotrius(allied species in the Himalayas);Cochoa(allied species in the
Himalayas);Crypsirhina(allied species in Burmah);Estrilda(allied species in
India);Psaltria(allied genus—Ægithaliscus—in Himalayas);Pavo
muticusandHarpactes oreskios(same species in Siam and Burmah);Cecropis
striolata(same species in Java and Formosa, and allied species in India). Here we have 12 instances of very remarkable distribution, and considering that there are
nearly as many birds known from Sumatra and Borneo as from Java, and considerably more fromthe Malay peninsula, it is not likely that many of these
well marked forms will be discovered in these countries. There are also a considerable number of species of birds common to Malacca,
Sumatra, and Borneo, but represented in Java by distinct though closely allied species. Such
are,— Now if we look at our map of the region, and consider the position of Java with regard to
Borneo, Sumatra, and the Indo-Chinese peninsula, the facts just pointed out appear most anomalous
and perplexing. First, we have Java and Sumatra forming one continuous line of volcanoes,
separated by a very narrow strait, and with all the appearance of having formed one continuous
land; yet their productions differ considerably, and those of Sumatra show the closest resemblance
to those of Borneo, an island ten times further off than Java and differing widely in the absence
of volcanoes or any continuous range of lofty mountains. Then again, not only does Java differ
from these two, but it agrees with a country beyond them both—a country from which they seem
to have a much better chance to have been supplied by immigration than Java has, and to have
(almost necessarily) participated, even more largely, in the benefits of any means of transmission
capable of reaching the latter island. Yet more; whatever changes have occurred to bring about the
anomalous state of things that exists must have been, zoologically and geologically, recent; for
the strange cross-affinities between Java and the Indo-Chinese continent (in which Sumatra and
Borneo have not participated), as well as that between Malacca, Sumatra, and Borneo (in which Java
has not participated) are exhibited, in many cases by community ofspecies, in others by
the presence of very closely allied forms of the samegenera, of mammalia and birds. Now we
know thatthese higher animals become replaced by
allied species much more rapidly than the mollusca; and it is also pretty certain that the
modification by which this replacement is effected takes place more rapidly when the two sets of
individuals are isolated from each other, and especially when they are restricted to islands,
where they are necessarily subject to distinct and pretty constant conditions, both physical and
organic. It becomes therefore almost a certainty, that Siam and Java on the one hand, and Sumatra,
Borneo, and Malacca on the other must have been brought into some close connexion, not earlier
than the newer Pliocene period; but while the one set of countries were having their meeting, the
other must have been by some means got out of the way. Before attempting to indicate the mode by
which this might have been effected in accordance with what we know of the physical geography,
geology, and vegetation of the several islands, it will be as well to complete our sketch of their
zoological relations to each other, so as ascertain with some precision, what are the facts of
distribution which we have to explain. Malacca, Sumatra, and Borneo.—After having set apart the Philippine Islands and
Java, we have remaining two great islands and a peninsula, which, though separated by considerable
arms of the sea, possess a fauna of wonderful uniformity having all the typical Malayan features
in their full development. Their unity is indeed so complete, that we can find hardly any groups
of sufficient importance by which to differentiate them from each other; and we feel no confidence
that future discoveries may not take away what speciality they possess. One after another, species
or genera once peculiar to Borneo or Sumatra have been found elsewhere; and this has gone to such
an extent in birds, that hardly a peculiar genus and very few peculiar species are left in either
island. Borneo however is undoubtedly the most peculiar. It possesses three genera of Mammalia not
found elsewhere;Cynogale, a curious carnivore allied to the otters; withDendrogaleandPtilocerus, small insectivora allied toTupaia. It hasSimia, theOrang-utan, andPaguma, one of the Viverridæ, in
common with Sumatra; as well asRhinosciurus, a peculiar form of squirrel, andHemigalea, one of the Viverridæ, in common with Malacca. Sumatra has only one genus not
found in any other Malayan district—Nemorhedus, a form of antelope which occurs again
in North India. It also hasSiamangain common with Malacca,Mydauswith Java, andRhizomyswith India. The Malay Peninsula seems to have no peculiar forms of Mammalia,
though it is rich in all the characteristic Malay types. The bats of the various islands have been very unequally collected, 36 species
being recorded from Java, 23 from Sumatra, but only 16 each from Borneo and Malacca. Leaving these
out of consideration, and taking into account the terrestrial mammals only, we find that Java is
the poorest in species, while Borneo, Sumatra, and Malacca are tolerably equal; the numbers being
55, 62, 66, and 65 respectively. Of these we find that the species confined to each island or
district are (in the same order) 6, 16, 5, and 6. It thus appears that Borneo is, in its mammalia,
the most isolated and peculiar; next comes Sumatra, and then Malacca and Java, as shown by the
following table. This result differs from that which we have arrived at by the more detailed consideration of
the fauna of Java; and it serves to show that the estimate of a country by the number of its
peculiar genera and species alone, may not always represent its true zoological importance or its
most marked features. Java, as we have seen, is differentiated from the other three districts by
the absence of numerous types common to them all, and by its independent continental relations.
Borneo is also well distinguished by its peculiar genera and specific types, yet it is at the same
time more closely related to Sumatra and Malacca than is Java. The two islands have evidently had
a very different history, which a detailed knowledge of their geologywould alone enable us to trace. Should we ever arrive at a fair knowledge
of the physical changes that have resulted in the present condition, we shall almost certainly
find that many of the differences and anomalies of their existing fauna and flora will be
accounted for. In Birds we hardly find anything to differentiate Borneo and Sumatra in any clear manner.PityriasisandCarpococcyx, once thought peculiar to the former, are now found also
in the latter; and we have not a single genus left to characterize Borneo exceptSchwaneriaa peculiar fly-catcher, andIndicator, an African and Indian group not known to occur
elsewhere in the Malay sub-region. Sumatra as yet alone possessesPsilopogon, a remarkable
form of barbet, but we may well expect that it will be soon found in the interior of Borneo or
Malacca; it also hasBerenicornis, an African form of hornbill. The Malay Peninsula appears
to have no genus peculiar to it, but it possesses some Chinese and Indian forms which do not pass
into the islands. As to the species, our knowledge of them is at present very imperfect. The Malay
Peninsula is perhaps the best known, but it is probable that both Sumatra and Borneo are quite as
rich in species. With the exception of the genera noted above, and two or three others as yet
found in two islands only, the three districts we are now considering may be said to have an
almost identical bird-fauna, consisting largely of the same species and almost wholly of these
together with closely allied species of the same genera. There are no well-marked groups which
especially characterise one of these islands rather than the other, so that even the amount of
speciality which Borneo undoubtedly exhibits as regards mammalia, is only faintly shown by its
birds. The Pittidæ may perhaps be named as the most characteristic Bornean group, that island
possessing six species, three of which are peculiar to it and are among the most beautiful birds
of an unusually beautiful family. Yet Sumatra possesses two peculiar, and hardly less remarkable
species. In other classes of vertebrates, in insects, and in land-shells, our knowledge is far too
imperfect to allow of our making any useful comparison between the faunas.
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