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Table of Contents

CLASSIFICATION OF THE FACTS OF DISTRIBUTION.—ZOOLOGICAL REGIONS

The Geographical Divisions of the Globe do not correspond to Zoological divisions—The range of British Mammals as indicating a Zoological Region—Range of East Asian and North African Mammals—The Range of British Birds—Range of East Asian Birds—The limits of the Palæarctic Region—Characteristic features of the Palæarctic Region—Definition and characteristic groups of the Ethiopian Region—Of the Oriental Region—Of the Australian Region—Of the Nearctic Region—Of the Neotropical Region—Comparison of Zoological Regions with the Geographical Divisions of the Globe.

Having now obtained some notion of how animals are dispersed over the earth's surface, whether as single species or as collected in those groups termed genera, families, and orders, it will be well, before proceeding further, to understand something of the classification of the facts we have been considering, and some of the simpler conclusions these facts lead to.

We have hitherto described the distribution of species and groups of animals by means of the great geographical divisions of the globe in common use; but it will have been observed that in hardly any case do these define the limits of anything beyond species, and very seldom, or perhaps never, even those accurately. Thus the term "Europe" will not give, with any approach to accuracy, the range of any one genus of mammals or birds, and perhaps not that of half-a-dozen species. Either they range into Siberia, or Asia Minor, or Palestine, or North Africa; and this seems to be always the case when their area of distribution occupies a large portion of Europe. There are, indeed, a few species limited to Central or Western or Southern Europe, and these are almost the only cases in which we can use the word for zoological purposes without having to add to it some portion of another continent. Still less useful is the term Asia for this purpose, since there is probably no single animal or group confined to Asia which is not also more or less nearly confined to the tropical or the temperate portion of it. The only exception is perhaps the tiger, which may really be called an Asiatic animal, as it occupies nearly two-thirds of the continent; but this is an unique example, while the cases in which Asiatic animals and groups are strictly limited to a portion of Asia, or extend also into Europe or into Africa or to the Malay Islands, are exceedingly numerous. So, in Africa, very few groups of animals range over the whole of it without going beyond either into Europe or Asia Minor or Arabia, while those which are purely African are generally confined to the portion south of the tropic of Cancer. Australia and America are terms which better serve the purpose of the zoologist. The former defines the limit of many important groups of animals; and the same may be said of the latter, but the division into North and South America introduces difficulties, for almost all the groups especially characteristic of South America are found also beyond the isthmus of Panama, in what is geographically part of the northern continent.

It being thus clear that the old and popular divisions of the globe are very inconvenient when used to describe the range of animals, we are naturally led to ask whether any other division can be made which will be more useful, and will serve to group together a considerable number of the facts we have to deal with. Such a division was made by Mr. P. L. Sclater more than twenty years ago, and it has, with some slight modifications, come into pretty general use in this country, and to some extent also abroad; we shall therefore proceed to explain its nature and the principles on which it is established, as it will have to be often referred to in future chapters of this work, and will take the place of the old geographical divisions whose inconvenience has already been pointed out. The primary zoological divisions of the globe are called "regions," and we will begin by ascertaining the limits of the region of which our own country forms a part.

The Range of British Mammals as indicating a Zoological Region.—We will first take our commonest wild mammalia and see how far they extend, and especially whether they are confined to Europe or range over parts of other continents:

1. Wild Cat	Europe	N. Africa	Siberia, Afghanistan.
2. Fox	Europe	N. Africa	Central Asia to Amoor.
3. Weasel	Europe	N. Africa	Central Asia to Amoor.
4. Otter	Europe	N. Africa	Siberia.
5. Badger	Europe	N. Africa	Central Asia to Amoor.
6. Stag	Europe	N. Africa	Central Asia to Amoor.
7. Hedgehog	Europe	—	Central Asia to Amoor.
8. Mole	Europe	—	Central Asia.
9. Squirrel	Europe	—	Central Asia to Amoor.
10. Dormouse	Europe	—	—
11. Water-rat	Europe	—	Central Asia to Amoor.
12. Hare	Europe	—	W. Siberia, Persia.
13. Rabbit	Europe	N. Africa	—

We thus see that out of thirteen of our commonest quadrupeds only one is confined to Europe, while seven are found also in Northern Africa, and eleven range into Siberia, most of them stretching quite across Asia to the valley of the Amoor on the extreme eastern side of that continent. Two of the above-named British species, the fox and weasel, are also inhabitants of the New World, being as common in the northern parts of North America as they are with us; but with these exceptions the entire range of our commoner species is given, and they clearly show that all Northern Asia and Northern Africa must be added to Europe in order to form the region which they collectively inhabit. If now we go into Central Europe and take, for example, the quadrupeds of Germany, we shall find that these too, although much more numerous, are confined to the same limits, except that some of the more arctic kinds, as already stated, extend into the colder regions of North America.

Range of East Asian and North African Mammals.—Let us now pass to the other side of the great northern continent, and examine the list of the quadrupeds of Amoorland, in the same latitude as Germany. We find that there are forty-four terrestrial species (omitting the bats, the seals, and other marine animals), and of these no less than twenty-six are identical with European species, and twelve or thirteen more are closely allied representatives, leaving only five or six which are peculiarly Asiatic. We can hardly have a more convincing proof of the essential oneness of the mammalia of Europe and Northern Asia.

In Northern Africa we do not find so many European species (though even here they are very numerous) because a considerable number of West Asiatic and desert forms occur. Having, however, shown that Europe and Western Asia have almost identical animals, we may treat all these as really European, and we shall then be able to compare the quadrupeds of North Africa with those of Europe and West Asia. Taking those of Algeria as the best known, we find that there are thirty-three species identical with those of Europe and West Asia, while twenty-four more, though distinct, are closely allied, belonging to the same genera; thus making a total of fifty-seven of European type. On the other hand, we have seven species which are either identical with species of tropical Africa or allied to them, and six more which are especially characteristic of the African and Asiatic deserts which form a kind of neutral zone between the temperate and tropical regions. If now we consider that Algeria and the adjacent countries bordering the Mediterranean form part of Africa, while they are separated from Europe by a wide sea and are only connected with Asia by a narrow isthmus, we cannot but feel surprised at the wonderful preponderance of the European and West Asiatic elements in the mammalia which inhabit the district.

The Range of British Birds.—As it is very important that no doubt should exist as to the limits of the zoological region of which Europe forms a part, we will now examine the birds, in order to see how far they agree in their distribution with the mammalia. Of late years great attention has been paid to the distribution of European and Asiatic birds, many ornithologists having travelled in North Africa, in Palestine, in Asia Minor, in Persia, in Siberia, in Mongolia, and in China; so that we are now able to determine the exact ranges of many species in a manner that would have been impossible a few years ago. These ranges are given for all British species in the new edition of Yarrell's History of British Birds edited by Professor Newton, while those of all European birds are given in still more detail in Mr. Dresser's beautiful work on the birds of Europe. In order to confine our examination within reasonable limits, and at the same time give it the interest attaching to familiar objects, we will take the whole series of British Passeres or perching birds given in Professor Newton's work (118 in number) and arrange them in series according to the extent of their range. These include not only the permanent residents and regular migrants to our country, but also those which occasionally straggle here, so that it really comprises a large proportion of all European birds.

I. British Birds which extend to North Africa and Central or North-east Asia.
1. Lanius collurio	Red backed Shrike (also all Africa).
2. Oriolus Galbula	Golden Oriole (also all Africa).
3. Turdus musicus	Song-Thrush.
4. ,, iliacus	Red-wing.
5. ,, pilaris	Fieldfare.
6. Monticola saxatilis	Blue rock Thrush.
7. Ruticilla suecica	Bluethroat (also India in winter).
8. Saxicola rubicola	Stonechat (also India in winter).
9. ,, œnanthe	Wheatear (also N. America).
10. Acrocephalus arundinaceus	Great Reed-Warbler.
11. Sylvia curruca	Lesser Whitethroat.
12. Parus major	Great Titmouse.
13. Motacilla sulphurea	Grey Wagtail (also China and Malaya).
14. ,, raii	Yellow Wagtail.
15. Anthus trivialis	Tree Pipit.
16. ,, spiloletta	Water Pipit.
17. ,, campestris	Tawny Pipit.
18. Alauda arvensis	Skylark.
19. ,, cristata	Crested Lark.
20. Emberiza schœniclus	Reed Bunting.
21. ,, citrinella	Yellow-hammer.
22. Fringilla montifringilla	Brambling.
23. Passer montanus	Tree Sparrow (also S. Asia).
24. ,, domesticus	House Sparrow.
25. Coccothraustes vulgaris	Hawfinch.
26. Carduelis spinus	Siskin (also China).
27. Loxia curvirostra	Crossbill.
28. Sturnus vulgaris	Starling.
29. Pyrrhocorax graculus	Chough.
30. Corvus corone	Crow.
31. Hirundo rustica	Swallow (all Africa and Asia).
32. Cotyle riparia	Sand Martin (also India and N. America).
II. British Birds which range to Central or North-east Asia.
1. Lanius excubitor	Great Grey Shrike.
2. Turdus varius	White's Thrush (also to Japan).
3. ,, atrigularis	Black-throated Thrush.
4. Acrocephalus nævius	Grasshopper Warbler.
5. Phylloscopus superciliosus	Yellow-browed Warbler.
6. Certhia familiaris	Tree-creeper.
7. Parus cœruleus	Blue Titmouse.
8. ,, ater	Coal Titmouse.
9. ,, palustris	Marsh Titmouse.
10. Acredula caudata	Long-tailed Titmouse.
11. Ampelis garrulus	Wax-wing.
12. Anthus richardi	Richard's Pipit.
13. Alauda alpestris	Shore Lark (also N. America).
14. Plectrophanes nivalis	Snow-Bunting (also N. America).
15. ,, lapponicus	Lapland Bunting.
16. Emberiza rustica	Rustic Bunting (also China).
17. ,, pusilla	Little Bunting.
18. Linota linaria	Mealy Redpole (also N. America).
19. Pyrrhula erythrina	Scarlet Grosbeak (also N. India, China).
20. ,, enucleator	Pine Grosbeak (also N. America).
21. Loxia bifasciata	Two-barred Crossbill.
22. Pastor roseus	Rose-coloured Starling (also India).
23. Corvus corax	Raven (also N. America).
24. Pica rustica	Magpie.
25. Nucifraga caryocatactes	Nutcracker.
III. British Birds ranging into N. Africa and W. Asia.
1. Lanius minor	Lesser Grey Shrike.
2. ,, auriculatus	Woodchat (also Tropical Africa).
3. Muscicapa grisola	Spotted Flycatcher (also E. and S. Africa).
4. ,, atricapilla	Pied Flycatcher (also Central Africa).
5. Turdus viscivorus	Mistletoe-Thrush (N. India in winter).
6. ,, merula	Blackbird.
7. ,, torquatus	Ring Ouzel.
8. Accentor modularis	Hedge Sparrow.
9. Erithacus rubecula	Redbreast.
10. Daulias luscinia	Nightingale.
11. Ruticilla phænicurus	Redstart.
12. ,, tithys	Black Redstart.
13. Saxicola rubetra	Whinchat.
14. Aëdon galactodes	Rufous Warbler.
15. Acrocephalus streperus	Reed Warbler.
16. ,, schænobenus	Sedge Warbler.
17. Melizophilus undatus	Dartford Warbler.
18. Sylvia rufa	Greater Whitethroat.
19. ,, salicaria	Garden Warbler.
20. ,, atricapilla	Blackcap.
21. ,, orphea	Orphean Warbler.
22. Phylloscopus sibilatrix	Wood Wren.
23. ,, trochilus	Willow Wren.
24. ,, collybita	Chiffchaff.
25. Regulus cristatus	Golden-crested Wren.
26. ,, ignicapillus	Fire-crested Wren.
27. Troglodytes parvulus	Wren.
28. Sitta cæsia	Nuthatch.
29. Motacilla alba	White Wagtail (also W. Africa).
30. ,, flava	Blue-headed Wagtail.
31. Anthus pratensis	Meadow-Pipit.
32. Alauda arborea	Woodlark.
33. Calandrella brachydactyla	Short-toed Lark.
34. Emberiza miliaria	Common Bunting.
35. ,, cirlus	Cirl Bunting.
36. ,, hortulana	Ortolan.
37. Fringilla cœlebs	Chaffinch.
38. Coccothraustes chloris	Greenfinch.
39. Serinus hortulanus	Serin.
40. Carduelis elegans	Goldfinch.
41. Linota cannabina	Linnet.
42. Corvus monedula	Jackdaw.
43. Chelidon urbica	House-Martin.
IV. British Birds ranging to North Africa.
1. Hypolais icterina	Icterine Warbler.
2. Acrocephalus aquaticus	Aquatic Warbler.
3. ,, luscinioides	Savi's Warbler.
4. Motacilla lugubris	Pied Wagtail.
5. Pyrrhula europæa	Bullfinch.
6. Garrulus glandarius	Jay.
V. British Birds ranging to West Asia only.
1. Accentor collaris	Alpine Accentor.
2. Muscicapa parva	Red-breasted Flycatcher (to N. W. India).
3. Panurus biarmicus	Bearded Titmouse.
4. Melanocorypha sibirica	White-winged Lark.
5. Euspiza melanocephala	Black-headed Bunting.
6. Linota flavirostris	Twite.
7. Corvus frugilegus	Rook.
VI. British Birds confined to Europe.
1. Cinclus aquaticus	Dipper (closely allied races inhabit other parts of the Palæarctic Region).
2. Parus cristatus	Crested Titmouse.
3. Anthus obscurus	Rock Pipit.
4. Linota rufescens	Lesser Redpoll (closely allied races in N. Asia and N. America).
5. Loxia pityopsittacus	Parrot Crossbill (a closely allied form in N. Asia).

We find, that out of a total of 118 British Passeres there are:

32 species which range to North Africa and Central or East Asia.

25 species which range to Central or East Asia, but not to North Africa.

43 species which range to North Africa and Western Asia.

6 species which range to North Africa, but not at all into Asia.

7 species which range to West Asia, but not to North Africa.

5 species which do not range out of Europe.

These figures agree essentially with those furnished by the mammalia, and complete the demonstration that all the temperate portions of Asia and North Africa must be added to Europe to form a natural zoological division of the earth. We must also note how comparatively few of these overpass the limits thus indicated; only seven species extending their range occasionally into tropical or South Africa, eight into some parts of tropical Asia, and six into arctic or temperate North America.

Range of East Asian Birds.—To complete the evidence we only require to know that the East Asiatic birds are as much like those of Europe, as we have already shown to be the case when we take the point of departure from our end of the continent. This does not follow necessarily, because it is possible that a totally distinct North Asiatic fauna might there prevail; and, although our birds go eastward to the remotest parts of Asia, their birds might not come westward to Europe. The birds of Eastern Siberia have been carefully studied by Russian naturalists and afford us the means of making the required comparison. There are 151 species belonging to the orders Passeres and Picariæ (the perching and climbing birds), and of these no less than 77, or more than half, are absolutely identical with European species; 63 are peculiar to North Asia, but all except five or six of these are allied to European forms; the remaining 11 species are migrants from South-eastern Asia. The resemblance is therefore equally close whichever extremity of the Euro-Asiatic continent we take as our starting point, and is equally remarkable in birds as in mammalia. We have now only to determine the limits of this, our first zoological region, which has been termed the "Palæarctic" by Mr. Sclater, meaning the "northern old-world" region—a name now well known to naturalists.

The Limits of the Palæarctic Region.—The boundaries of this region, as nearly as they can be ascertained, are shown on our general map at the beginning of this chapter, but it will be evident on consideration, that, except in a few places, its limits can only be approximately defined. On the north, east, and west it extends to the ocean, and includes a number of islands whose peculiarities will be pointed out in a subsequent chapter; so that the southern boundary alone remains, but as this runs across the entire continent from the Atlantic to the Pacific ocean, often traversing little-known regions, we may perhaps never be able to determine it accurately, even if it admits of such determination. In drawing the boundary line across Africa we meet with our first difficulty. The Euro-Asiatic animals undoubtedly extend to the northern borders of the Sahara, while those of tropical Africa come up to its southern margin, the desert itself forming a kind of sandy ocean between them. Some of the species on either side penetrate and even cross the desert, but it is impossible to balance these with any accuracy, and it has therefore been thought best, as a mere matter of convenience, to consider the geographical line of the tropic of Cancer to form the boundary. We are thus enabled to define the Palæarctic region as including all north temperate Africa; and, a similar intermingling of animal types occurring in Arabia, the same boundary line is continued to the southern shore of the Persian Gulf. Persia and Afghanistan undoubtedly belong to the Palæarctic region, and Baluchistan should probably go with these. The boundary in the north-western part of India is again difficult to determine, but it cannot be far one way or the other from the river Indus as far up as Attock, opposite the mouth of the Cabool river. Here it will bend to the south-east, passing a little south of Cashmeer, and along the southern slopes of the Himalayas into East Thibet and China, at heights varying from 9,000 to 11,000 feet according to soil, aspect, and shelter. It may, perhaps, be defined as extending to the upper belt of forests as far as coniferous trees prevail; but the temperate and tropical faunas are here so intermingled that to draw any exact parting line is impossible. The two faunas are, however, very distinct. In and above the pine woods there are abundance of warblers of northern genera, with wrens, numerous titmice, and a great variety of buntings, grosbeaks, bullfinches and rosefinches, all more or less nearly allied to the birds of Europe and Northern Asia; while a little lower down we meet with a host of peculiar birds allied to those of tropical Asia and the Malay Islands, but often of distinct genera. There can be no doubt, therefore, of the existence here of a pretty sharp line of demarkation between the temperate and tropical faunas, though this line will be so irregular, owing to the complex system of valleys and ridges, that in our present ignorance of much of the country it cannot be marked in detail on any map.

Further east in China it is still more difficult to determine the limits of the region, owing to the great intermixture of migrating birds; tropical forms passing northwards in summer as far as the Amoor river, while the northern forms visit every part of China in winter. From what we know, however, of the distribution of some of the more typical northern and southern species, we are able to fix the limits of the Palæarctic region a little south of Shanghai on the east coast. Several tropical genera come as far north as Ningpo or even Shanghai, but rarely beyond; while in Formosa and Amoy tropical forms predominate. Such decidedly northern forms as bullfinches and hawfinches are found at Shanghai; hence we may commence the boundary line on the coast between Shanghai and Ningpo, but inland it probably bends a little southward, and then northward to the mountains and valleys of West China and East Thibet in about 32° N. latitude; where, at Moupin, a French missionary, Père David, made extensive collections showing this district to be at the junction of the tropical and temperate faunas. Japan, as a whole, is decidedly Palæarctic, although its extreme southern portion, owing to its mild insular climate and evergreen vegetation, gives shelter to a number of tropical forms.

Characteristic Features of the Palæarctic Region.—Having thus demonstrated the unity of the Palæarctic region by tracing out the distribution of a large proportion of its mammalia and birds, it only remains to show how far it is characterised by peculiar groups such as genera and families, and to say a few words on the lower forms of life which prevail in it.

Taking first the mammalia, we find this region distinguished by possessing two peculiar genera of Talpidæ or moles, the family being confined to the Palæarctic and Nearctic regions. The true hedgehogs (Erinaceus) are also characteristic, being only found elsewhere in South Africa and in the northern part of the Oriental region. Among Carnivora, the racoon-dog (Nyctereutes) of North-eastern Asia, and the true badgers of the genus Meles are peculiar, most other parts of the world possessing distinct genera of badgers. It has six peculiar genera, or subgenera, of deer; seven peculiar genera of Bovidæ, chiefly antelopes; while the entire group of goats and sheep, comprising twenty-two species, is almost confined to it, one species only occurring in the Rocky mountains of North America and another in the Nilgiris of Southern India. Among the rodents there are nine genera with twenty-seven species wholly confined to it, while several others, as the hamsters, the dormice, and the pikas, have only a few species elsewhere.

In birds there are a large number of peculiar genera of which we need mention only a few of the more important, as the grass-hopper warblers (Locustella) with seven species, the Accentors with twelve species, and about a dozen other genera of warblers, including the robins; the bearded titmouse and several allied genera; the long-tailed titmice forming the genus Acredula; the magpies, choughs, and nut-crackers; a host of finches, among which the bullfinches (Pyrrhula) and the buntings (Emberiza) are the most important. The true pheasants (Phasianus) are wholly Palæarctic, except one species in Formosa, as are several genera of wading birds. Though the reptiles of cold countries are few as compared with those of the tropics, the Palæarctic region in its warmer portions has a considerable number, and among these are many which are peculiar to it. Such are four genera of snakes, seven of lizards, five of frogs and toads, and twelve of newts and salamanders; while of fresh-water fishes there are about twenty peculiar genera.^[7] Among insects we may mention the elegant Apollo butterflies of the Alps as forming a peculiar genus (Parnassius), only found elsewhere in the Rocky Mountains of North America, while the beautiful genus Thais of the south of Europe and Sericinus of North China are equally remarkable. Among other insects we can only now refer to the great family of Carabidæ, or predaceous ground-beetles, which are immensely numerous in this region, there being about fifty peculiar genera; while the large and handsome genus Carabus, with its allies Procerus and Procrustes, containing nearly 300 species, is almost wholly confined to this region, and would alone serve to distinguish it zoologically from all other parts of the globe.

Having given so full an exposition of the facts which determine the extent and boundaries of the Palæarctic region, there is less need of entering into much detail as regards the other regions of the Eastern Hemisphere; their boundaries being easily defined, while their forms of animal life are well marked and strongly contrasted.

Definition and Characteristic Groups of the Ethiopian Region.—The Ethiopian region consists of all tropical and south Africa, to which are appended the large island of Madagascar and the Mascarene Islands to the east and north of it, though these differ materially from the continent, and will have to be discussed in a separate chapter. For the present, then, we will take Africa south of the tropic of Cancer, and consider how far its animals are distinct from those of the Palæarctic region.

Taking first the mammalia, we find the following remarkable animals at once separating it from the Palæarctic and every other region. The gorilla and chimpanzee, the baboons, numerous lemurs, the spotted hyæna, the aard-wolf and hyæna-dog, zebras, the hippopotamus, giraffe, and more than seventy peculiar antelopes. Here we have a wonderful collection of large and peculiar quadrupeds, but the Ethiopian region is also characterised by the absence of others which are not only abundant in the Palæarctic region but in many tropical regions as well. The most remarkable of these deficiencies are the bears the deer and the wild oxen, all of which abound in the tropical parts of Asia while bears and deer extend into both North and South America. Besides the large and conspicuous animals mentioned above, Africa possesses a number of completely isolated groups; such are the potamogale, a curious otter-like water-shrew, discovered by Du Chaillu in West Africa, so distinct as to constitute a new family, Potamogalidæ; the goldenmoles, also forming a peculiar family, Chrysochloridæ; as do the elephant-shrews, Macroscelididæ; the singular aard-varks, or earth-pigs, forming a peculiar family of Edentata called Orycteropodidæ; while there are numerous peculiar genera of monkeys, swine, civets, and rodents.

Among birds the most conspicuous and remarkable are, the great-billed vulture-crows (Corvultur), the long-tailed whydah finches (Vidua), the curious ox-peckers (Buphaga), the splendid metallic starlings (Lamprocolius), the handsome plantain-eaters (Musophaga), the ground-hornbills (Bucorvus), the numerous guinea-fowls belonging to four distinct genera, the serpent-eating secretary-bird (Serpentarius), the huge boat-billed heron (Balæniceps), and the true ostriches. There are also three quite peculiar African families, the Musophagidæ or plantain-eaters, including the elegant crested touracos; the curious little finch-like colies (Coliidæ), and the Irrisoridæ, insect-eating birds allied to the hoopoes but with glossy metallic plumage and arboreal habits.