HISTORICAL AND GEOGRAPHICAL 



ii 



particular insular fauna is made, careful consideration must be given to 

 the nature, both geological and physical, of the island- itself. Following 

 Wallace, we may arrange all islands in two categories, viz., continental and 

 oceanic. By a continental island is meant one lying comparatively near one 

 of the great continental masses, and as a rule containing in its geological 

 formation stratified rocks of various ages. Such an island has at one time 

 or other been connected with the adjacent continent, having been separated 

 by the submergence of the intervening area. Hence its fauna is more or 

 less similar to that of the neighbouring mainland, and always includes a 

 certain proportion of Mammals and Amphibians. Moreover, the number 

 and nature of its special forms depend to a great extent upon the length of 

 time which has elapsed since the separation took place. As examples of 

 such islands we may take Great Britain, Borneo, Java, the Philippine 

 Islands, Japan and Formosa. A certain number of continental islands are 

 separated by water of considerable depth, amounting even to more than a 

 thousand fathoms. Such are regarded as of more ancient origin than the 

 rest, and the deficient yet highly peculiar nature of their fauna corroborates 

 this view. They may even be the remains of some large continent which 

 has disappeared beneath the waves, leaving only isolated and elevated 

 portions which now figure as islands, with a fauna related, it may be, to 

 quite remote parts of the earth's surface. Madagascar and its neighbouring 

 groups of islands form, perhaps, the best example of this class. 



An oceanic island, on the other hand, is one which has never been 

 attached to any continent, but has been formed independently in mid-ocean, 

 either by volcanic agency or through the building up of coral reefs, or again 

 by a combination of both methods. The fauna of such islands is usually 

 characterised by an entire absence of terrestrial Mammals and Amphibians, 

 but includes a fair proportion of very peculiar birds and insects, and often a 

 few reptiles. Many well-known islands may be included here, such as the 

 Sandwich and Galapagos Islands, St Helena, the Azores, Bermuda and 

 Kerguelen. 



For a masterly and exhaustive account of insular faunas, the reader 

 should consult the classical work of Alfred Russel Wallace, bearing the 

 title Island Life {vide Bibliography). From this volume, the following short 

 summary has been compiled. 



OCEANIC ISLANDS. 



The Azores. — In this group of islands there are no indigenous terrestrial 

 Mammals, and Amphibians are also absent. Birds are represented by 53 

 species, 31 of which are either aquatic or waders, and chiefly occur as 

 migrants. Of the remaining 22 species, which are land Birds, four are 

 merely stragglers. There are thus 18 permanent residents, 15 of which are 

 natives of Europe and North Africa. A single species, the Azorean Bull- 

 finch {Pyrrliula murina) is peculiar. In the great class of insects, the 

 Lepidoptera (Butterflies and Moths) and Hymenoptera (Ants, Bees, Wasps, 

 <fec.) are sparsely represented, the species being almost all European ones. 

 Of Coleoptera (Beetles) there are 212 species, of which 175 are European. 

 Of these 101 are probably introduced and 74 indigenous. The peculiar 

 species number 14. There are 69 species of terrestrial Mollusca, of which 

 37 are European and 32 peculiar. 



Bermuda. — No terrestrial Mammals occur in these islands, but four 

 species of Bat occur rarely. Frogs and Snakes are absent, but there is one 

 Lizard, which is a peculiar species. Of Birds 180 species are recorded, 85 of 

 which are Land Birds. Of these, about a quarter are regular visitors, 

 while only 11 are permanent residents. Eight of the latter are land, 

 and the other three aquatic Birds, and all are common on the North 

 American mainland. Insects are comparatively scarce. Of Coleoptera 

 (Beetles) 19 species are recorded ; of Hymenoptera, 11 ; of Lepidoptera, 26 ; 

 Diptera, 9 ; Hemiptera, Orthoptera and Neuroptera, 9 each. All are 

 common North American or West Indian species. The Land Mollusca 

 comprise 28 species, six of which are peculiar. 



The Galapagos Islands. — As in the preceding group of islands, there 

 are no indigenous Mammals and no Amphibians. Reptiles, however, are 

 abundant and the gigantic Land Tortoises, found in these islands, are both 

 peculiar and of remarkable interest. Five species of Lizards occur, one of 

 the family Geckonidse and four of Iguanidse ; while there are also two 

 species of Snakes. 



The Birds are singularly interesting, inasmuch as 72 species, out of a total 

 of 100 occurring in the islands, are peculiar. Sixty-six out of this number 

 are land Birds, and of these only three are found elsewhere. 



Of Beetles about 40 species are recorded, mostly peculiar ; and of Land- 

 Shells about 46, two-thirds of which are Bulimuli, and most of which are 

 confined to these islands. 



St Helena. — In this island there are no indigenous Mammals, Land- 

 Birds, Reptiles or Fresh-water Fishes. One wader is present, namely, 

 a peculiar species of Plover [JSgialitis sanctse-helense). The Beetles 

 number 203 species, of which 74 have probably been introduced. 

 Strangely enough, about two-thirds of the remainder are Rhynchophora 

 (Weevils) — a proportion approached in no other part of the globe. Of 

 Land-Shells 29 species are recorded, 20 of which are indigenous. Of the 

 latter 13 appear to be extinct, being only represented by empty shells on or 

 below the surface of the ground. 



The Sandwich Islands. — These islands are so extensive and possess a 

 fauna so peculiar, that Lydekker regards them as forming a distinct 

 Zoo^eoo-raphical Region, and W, L. Sclater as a sub-region of the 

 Australian Region. While indigenous Mammals are entirely absent, the 

 Birds are numerous and present many peculiarities. Fifty-eight species of 

 aquatic and wading birds are recorded, of which six are peculiar, while four 

 birds of prey have occurred in these islands. The Passeriformes, or Perching 

 Birds are represented by 55 species, 41 of which belong to a peculiar family, 

 the Drepanididse, while Parrots, Pigeons and Kingfishers, all of which are 

 represented in the larger Pacific Islands, are entirely wanting. Two Lizards 

 complete the list of Vertebrates. 



Of Land and Fresh-water Mollusca, 477 species are recorded, 332 of 

 which belong to the peculiar family Achatinellidse. 1 It is interesting to 

 note, also, that the great majority of the species are confined to a single 

 island. About a thousand species of Coleoptera (Beetles) are known, nine- 

 tenths of which are peculiar. 



CONTINENTAL ISLANDS. 



The British Isles. — As compared with adjacent portions of the continent, 

 the British Isles exhibit a curious paucity of species among Mammals, 

 Reptiles and Amphibians — a fact accounted for by the glaciation of our 

 country at a comparatively recent period. This, together with submergence, 

 exterminated a large portion of the fauna, and the subsequent connection of 

 these islands with the continent was not of sufficient duration to allow of 

 the migration of many forms for which our climate and physical conditions 

 are suitable. 



Of terrestrial Mammals, Britain only possesses some 40 species, while 

 there are about 90 in Germany. Only one is peculiar, namely, the Orkney 

 Vole (Microtus orcadensis), but there are, in addition, several racial forms 

 confined to these islands. Again, Belgium has 22 species of Reptiles and 

 Amphibians, Britain only 13 and Ireland only four. Only a single species of 

 Bird is peculiar to the British Isles, namely, the Red Grouse (Lagopus 

 scotictis), but here again a number of species exhibit racial peculiarities. 

 Among these are Parus ater, sub.-sp. britannicus (Cole Tit), Acredula caudata, 

 sub.-sp. rosea (Long-tailed Tit), and Troglodytes parvulus, var. hirtensis (St 

 Kilda Wren). Of fresh-water Fishes several forms of the genus Salmo 

 (Trout and Charr) are peculiar to British and Irish lakes, while the 

 Lepidoptera (Butterflies and Moths) include 179, and the Coleoptera 

 (Beetles), 71 species and varieties, which are supposed to be confined to the 

 British Islands. Finally, the list of land and fresh-water Mollusca shows 

 122 peculiar species and varieties. 



Borneo and Java. — Out of 175 species of terrestrial Mammals occurring 

 in Borneo, 55 are peculiar, and 10 others present varieties confined to the 

 island. Of these, 7 are Monkeys, 10 Bats, 15 Insectivores, 4 Carnivores, 

 28 Rodents and 1 Ungulate (a Pig). Of Birds, the same island possesses 490 

 species, and of these no fewer than 126 are peculiar. In Java, on the other 

 hand, only 90 species of Mammals are found, only some half dozen being 

 peculiar ; while of birds there are only 300 species of which 45 are peculiar. A 

 number of typically Malayan animals are found in Borneo, but not in Java, 

 and among these may be mentioned the Elephant, Malayan Bear and Tapir. 

 There is a similar deficiency as regards the Javan Birds, certain genera of 

 forms so conspicuous as Jays, Woodpeckers, Hornbills, Cuckoos, Parrots 

 and Pheasants, being quite unknown, although these are of a Malayan type 

 and present in other East Indian islands. As Wallace says : "From these 

 facts, it is impossible to doubt that Java has had a history of its own, quite 

 distinct from that of the other portions of the Malayan area." 



The Philippine Islands. — In these very interesting islands there are 44 

 species of Mammals (excluding Bats), and of these no fewer than 33 are 

 peculiar. Of the 22 Rodents found in the islands and peculiar to them, 

 10 belong to quite peculiar genera. The other Mammals confined to the 

 Philippines are a Galeopithecus (Flying Lemur), a Tupaia (Tree Shrew), and 

 three other Insectivores ; a Tragidus (Chevrotain), and four species of 

 Cervus (Deer) ; and lastly, Buffelus mindorensis, a small Buffalo. Of land 

 Birds there are 442 species, with no less than 312 peculiar. 



Japan. — -Although occupying a very similar position with regard to the 

 adjacent continent of Asia to that occupied by the British Isles in relation 

 to Europe, the Japanese islands possess a far larger number of peculiar 

 forms. Thus, of the 42 species of Mammals, no fewer than 27 are peculiar, 

 including a Monkey, two Bats, six Insectivores, six Carnivores, nine 

 Rodents, two Deer and a Pig. The Erinaceidse (Hedgehogs), represented 

 by a single species in Britain, are absent, but the Ursidse (Bears), Bovidse. 

 (Oxen), and Suidse (Pigs), are all found in Japan. About 200 species of 

 Birds occur, 17 of which are peculiar. These are principally allied to North 

 Chinese and Siberian forms, but three are of a tropical character, and 

 include a Treron, or Fruit-Pigeon. 



Formosa. — In this island, whose southei-n portion enters the Tropics, 

 36 species of Mammals and 128 species of land Birds are recorded, and of 

 these 10 and 35 respectively are peculiar. The proportion of over a quarter 

 of peculiar land Birds is a very high one, considering the proximity of the 

 island to the mainland. Nearly half the peculiar species of Birds are most 

 closely allied to forms occurring in the Himalayas, Southern India, the Malay 

 Islands and Japan, but absent from the nearest portion of the mainland ; while 

 there are eight species common to Formosa and India or the Malay Islands, 

 not found in China. All these facts appear to indicate that a great change 

 must have taken place in the distribution of the Asiatic fauna since the 

 island now under consideration was separated from the adjacent continent. 



Celebes. — A good deal of difference of opinion has prevailed, and still 

 prevails, regarding the position which this island should occupy in the 

 schemes of Regions and Sub-regions mapped out for distributional pur- 

 poses. Originally it formed part of the Australian Region of P. L. Sclater 

 and Wallace, and by the latter author it was placed in his Austro-Malayan 

 Sub-region. Subsequently, however, it was transferred by W. L. and P. L. 

 Sclater to the Oriental Region, where it formed a separate Sub-region. 

 Heilprin regarded it as one of his "Transition Tracts/' while Lydekker 

 mapped it as a separate region, with both Oriental and Australian features. 



The detailed lists of animals occurring in this puzzling island are of 

 much interest. Of 40 species of terrestrial Mammals, 23 are peculiar, 

 including 3 Primates, 1 Carnivore, 15 Rodents, 2 Ungulates and 2 Mar- 

 supials. Cynopithecus niger (the Black Ape), Anoa depressicornis (the 

 Anoa), and Babirussa babirussa (the Babirussa), each belong to a peculiar 

 genus, and are perhaps the most interesting of all the Mammals found in 

 this island, since they have no close allies elsewhere. The Birds of Celebes 

 (excluding the small neighbouring islands) number 207 species, 114 of 

 which are peculiar, and many of which belong to peculiar genera. 



