The History of the European Fauna

by R. F. Scharff

In discussing the component elements of the British fauna and flora in the third chapter, I have already referred to the distinguishing characters of the Lusitanian migrants and to their distribution. I need only repeat, therefore, that these are now principally confined to the south-western portions of the British Islands. The late Edward Forbes was the first to trace the Lusitanian flora to its native home. In his classical memoir on the geological relations of the existing fauna and flora of the British Isles, he laid the foundations of a new method of research. We are as yet only beginning to realise the far-reaching conclusions obtainable by a careful study of the geographical distribution of animals and plants, though the lines of investigation were indicated by him more than fifty years ago. Forbes was of opinion that the Lusitanian element in the British flora was of miocene age, and that it survived the Glacial period on a now sunken land to the south-west of Ireland. Mr. Carpenter and myself agree in so far that we are both inclined to look upon this Lusitanian flora and the accompanying fauna in Ireland as of pre-glacial origin. But I am not quite satisfied that the Lusitanian migration ceased to come north then. It may have received a temporary check; but the presence, for instance, of the Dartford Warbler (Melizophilus undatus) in the south-east of England would seem to indicate that its northward migration took place in very recent times. It is possible also that the very restricted occurrence of the Dartford Warbler may imply that it is gradually withdrawing towards its centre of origin from a former wider range. Such an eventuality, as we have seen, has actually taken place in a great number of instances.

It is not only in the British Islands that we perceive the influence of the Lusitanian element. Scandinavia, Russia—indeed almost every part of Europe—can boast of some migrants which have originated in South-western Europe or on the mysterious lands which lay beyond it. As a rule, however, we notice a marked decrease of Lusitanian species as we travel eastward from Western Europe. Nevertheless, certain forms have travelled far beyond the confines of our continent, and we certainly meet with them in Asia and Northern Africa.

It is remarkable that we are apt to mistake sometimes for Lusitanian migrants species which are of Oriental origin. In a previous paper I classed such animals which had apparently originated in South-western Europe, but had really come from Asia by a circuitous southern route, with the Lusitanians. However, there is really no reason why the two should not be kept apart, provided we can discriminate between the pseudo-Lusitanians and the true ones. I have already indicated in the last chapter how these pseudo-Lusitanian migrants originated.

Supposing an Oriental species had left Asia for Europe in miocene times, it would on its arrival in Greece have had to decide between two courses. It could either advance into the newly-formed Alpine peninsula and there remain, or at once push on westward into Southern Italy, Sicily, and Tunis, by means of the old land-connections, and thence into Southern Spain. The Atlantic communicated at that time with the Mediterranean across the valley of the Guadalquivir; but that connection ceased to exist towards the end of the Miocene Epoch, when the Oriental migrants were free to ramble through Spain and the whole of the North European plain. I have indicated on a previous occasion (a, p. 484) that the earliest members of the Red Deer migration, which have left their traces in the caves of Malta, and whose descendants still live in Corsica, Sardinia, and North Africa, may have found their way to Northern Europe in this manner. Many other Asiatic mammals probably reached the British Islands in a similar way.

I cannot call to mind any large species of mammal which we might reasonably suppose to have originated in South-western Europe. Even among the smaller ones, few give us any definite clue in this respect. For instance, the present range of the genus Myogale—a small Insectivore belonging to the Mole family (Talpidæ)—teaches us nothing. The two living species show discontinuous distribution, and are almost confined to Europe. Myogale occurs fossil in French miocene deposits, but is unknown beyond the confines of our continent. It is therefore probably of West European origin. The gap between the South Russian M. moschata and the Spanish M. pyrenaica is bridged over in so far as we know from fossil evidence that the former had a much wider range in pleistocene times, being then found in England, Belgium, and Germany. Talpa, too,—to which genus our common Mole belongs,—seems to be a West European genus, since it occurs in French miocene deposits. However, it would be difficult to name many more recent genera which could be included in the area which I propose to investigate in this chapter. The genus Lepus is probably not of Lusitanian origin, but the sub-genus Oryctolagus—to which our common Rabbit belongs—has no doubt had its original home in that region. Only two species of Lepus (Oryctolagus) are known, one of which—Lepus lacostei—has been met with in French pliocene deposits. The other is the Rabbit (L. cuniculus). Though generally considered to have been introduced into the British Islands, no reason can be brought forward in favour of such a supposition, especially as it is known to have spread into Germany in pleistocene times from South-western Europe. It occurs in France, the Spanish peninsula, North-western Africa, and on some of the Mediterranean islands. Its nearest living relatives, as we should almost expect, are found in South America.

Of the Lusitanian Birds I have already mentioned the so-called Dartford Warbler (Melizophilus undatus), which ranges from the south of England to the extreme south-west of Europe. A second species occurs on the Balearic Islands and on Corsica, Sardinia, and Sicily. The Andalusian Bush-quail (Turnix sylvatica) is probably of North African origin, and has subsequently spread into Southern Spain and Portugal, and eastward as far as Sicily. It is an instance of a migrant utilising the old Mediterranean land-connections in the opposite direction from that described in the last chapter.

Two of our British Wagtails are very closely related, so much so that it requires a very critical eye to distinguish them even at close range. They also frequently interbreed. In their distribution, however, there is a considerable difference between the White Wagtail (Motacilla alba) and the Pied Wagtail (M. lugubris). While the former ranges almost all over Europe and Asia, the latter is a local form resident in the British Islands, Southern Scandinavia, and France, and a winter visitor to Spain and North-west Africa. The genus Motacilla is probably Oriental in its origin, but it seems as if the Pied Wagtail was a Lusitanian species which had gradually spread northward, only to return to South-western Europe in severe weather for shelter.

The Bearded Titmouse (Panurus biarmicus)—the only representative of the family Panuridæ—may possibly be a Lusitanian bird. The fact of its being absent from Scandinavia and Northern Russia is suggestive of a southern origin. It is doubtful whether the bird occurs on the south side of the Mediterranean, but it is common in the south of France and Spain, and has also been observed in Sicily, Greece, and Asia Minor. In Central Europe it is found sparingly, and eastward its range extends as far as Turkestan.

The genus Fringilla, which belongs to the great family of the Finches, appears to be not only of European origin, but, if the range of the species counts for anything, I should feel inclined to locate their home in the south-west. Altogether, five species are known. One of them, viz., Fringilla teydea, is confined to the Island of Teneriffe; another, F. madeirensis, is found in Madeira, the Canaries, and the Azores; a third, F. spodiogenys, inhabits North-west Africa. The two remaining species have a much wider range. F. cœlebs—the common Chaffinch—occurs in Europe, while its range extends eastward to Western Siberia, Persia, and Turkestan. The other—F. montifringilla, known as the Brambling—is more common in Northern Europe, and generally frequents the more northern latitudes of Asia as far as Japan.

It might be urged that the peculiar little blue Magpie of Spain—Cyanopolius Cooki—should find a place among the Lusitanian species, since there is no bird like it anywhere else in Europe. But in Eastern Siberia there lives a bird so closely allied as to be barely distinguishable from it. Nevertheless, since there are some distinguishing characters, it has received a distinct name—C. cyanus. This is a most interesting and remarkable case of discontinuous distribution, which may perhaps be explained by the supposition that the genus is of Oriental origin, and has died out at its former headquarters in Southern Asia and all along the line of migration, except at the extreme limits of the range in both directions—east and west.