The History of the European Fauna

by R. F. Scharff

CHAPTER VIII.
THE ALPINE FAUNA.

We are told by Sir Archibald Geikie (p. 851) that "from the Pyrenees eastwards, through the Alps and Apennines into Greece, and the southern side of the Mediterranean basin, through the Carpathian Mountains and the Balkan into Asia Minor, and thence through Persia and the heart of Asia to the shores of China and Japan, a series of massive limestones has been traced, which, from the abundance of their characteristic foraminifera, have been called the Nummulitic Limestone. Unlike the thin, soft, modern-looking, undisturbed beds of the Anglo-Parisian area, these limestones attain a depth of sometimes several thousand feet of hard, compact, sometimes crystalline rock, passing even into marble, and they have been folded and fractured on such a colossal scale that their strata have been heaved up into lofty mountain crests sometimes 10,000, and in the Himalaya range more than 16,000 feet above the sea." "Nowhere in Europe," continues the same author (p. 860), "do oligocene strata play so important a part in the scenery of the land, or present on the whole so interesting and full a picture of the state of Europe when they were deposited, as in Switzerland. Rising into massive mountains, as in the well-known Rigi and Rossberg, they attain a thickness of more than 6000 feet." "By far the larger portion of these strata is of lacustrine origin. They must have been formed in a large lake, the area of which probably underwent gradual subsidence during the period of deposition, until in Miocene times the sea once more overflowed the area."

From these remarks by our most eminent British geologist, we gather that in early Tertiary times much of the present area of Switzerland was either a sea or a large freshwater lake. The Alps were then appearing in this sea, probably as a chain of islands, and in the beginning of the Miocene Epoch one large elongated island had made its appearance—the future European Alps. I have already mentioned that the Miocene Sea skirted the Alps from the Mediterranean up the valley of the Rhone and along its northern and eastern margin. Miocene marine deposits are also known from the Southern Alps and the east side of the Apennines, from Corsica, Sardinia, and Malta. No trace, however, of them has been noticed anywhere along the Ægean Sea or on the Balkan peninsula. The Alps were therefore connected to the east with the outliers of the Balkan Mountains, and in this way with Asia, from which they received so large a proportion of their fauna and flora. In pliocene times the sea still washed the southern shore of the Alps, but to the north dry land gradually supplemented the sea, and the Alpine fauna and flora were able to pour into the plain. It was then that the Arctic species—which we have learned had migrated into Northern Europe from the north—found their way to the Alps. In a similar way Lusitanian forms—in fact, species from almost all parts of Europe—were now free to wander to the newly opened up peninsula which had become part of the mainland of Europe. The typical Siberian species had not entered our continent at that time, it was not till much later—not until the middle of the Pleistocene Epoch—that they made their appearance at the foot of the Alps, but, as we shall see later on, it is doubtful whether many of these species ever reached the mountains.

The fauna of the Alps, and also the flora, is therefore made up of a number of component elements. In the first place we have the Oriental element—the migrants from Central and Southern Asia. When the nature and origin of the Oriental fauna in Europe was discussed, reference was made to the fact (p. [272]) that we can distinguish an older from a newer Oriental migration. Both of these have entered the Alps. As we might anticipate, many of the older Oriental migrants have developed into new species, laying the foundation of an indigenous Alpine element. From the fact that they set foot on the Alpine peninsula, it might be expected that there could have existed no mountains to speak of. The climate was mild and damp. Now as the country rose, and a formidable mountain range took the place of a hilly island, the whole fauna was lifted up and transferred to entirely different conditions. A modification of their structure to suit the new surroundings was therefore to be anticipated, and that is exactly what occurred, though not in all cases.

Take, for example, the goats which are of Asiatic origin. Every one has heard of the "Steinbock,"—the Alpine mountain goat (Capra ibex)—though very few have seen it in its native haunts, where it is now on the verge of extinction. A closely allied species (Capra sibirica) inhabits the Altaï and Himalayan Mountains; a third species (Capra sinaitica) lives in Palestine, and has entered Egypt by way of the Sinaitic peninsula. Another (C. ægagrus) occurs in Asia Minor, Persia, the island of Crete, and some of the Cyclades. This exemplifies what I remarked in the last chapter about the former land-connection between Greece and the Asiatic continent. Finally, we have the Pyrenean Goat (Capra pyrenaica), which is found in the Pyrenees, the higher ranges of Central Spain, in Andalusia, and Portugal, thus indicating that it probably reached the Spanish peninsula from the south by means of the old Sicilo-Algerian highway, especially as remains of the species occur in the cave deposits of Gibraltar. The ancestors of the goat-like Antelope—known as the Chamois (Rupicapra tragus)—no doubt also came from Asia. The genus is not represented there, but Nemorhœdus and Budorcas are allied Asiatic genera, while the Rocky Mountain Goat (Haploceros montanus) also has certain affinities with the Chamois. Besides the Alps, the latter occurs in the Caucasus and the Pyrenees. The Alpine Marmot (Arctomys marmotta) is sometimes quoted as owing its origin to the Siberian pleistocene migration, but it does not occur in Siberia now, nor is there any palæontological evidence that it was ever found there. The genus Arctomys is an ancient Asiatic genus, to judge from its general range. Only two species occur in Europe, one of which, the true Siberian Marmot (A. bobac), just enters our continent in the east—or rather, it is one of those species which came to us in pleistocene times and are now gradually retreating towards their native land. The genus, however, is probably not of Siberian origin. No less than seven other species occur in Asia, six of which are confined to Central Asia and the Himalayan Mountains, while four have wandered to North America. The sequence of events, therefore, was that the ancestor of Arctomys marmotta probably came to the Alps direct from Central Asia by way of Asia Minor in miocene or pliocene times. It has since become modified into a distinct species, and has spread to the European plain, where it occurs fossil in pleistocene strata, and to the Carpathian Mountains and the Pyrenees.

The great majority of species of the large genus Microtus (Arvicola) are Asiatic, and there can be little doubt that it has originated in that continent. There is one species of Vole (Microtus nivalis) which occurs in the high Alps, and which has been supposed to be a typical Alpine form. It is known, however, to occur also in North Italy and in Bohemia, while Microtus leucurus of the Pyrenees is identical with this species. But its range is by no means confined to Europe, for it has also been discovered in Syria and Palestine, while a closely allied form exists in the Himalayan Mountains. This shows clearly that the species has migrated to the Alps from Asia Minor. That this migration may have taken place at an early period—at a time when Sardinia and Corsica were still connected with Southern Europe—is indicated by the occurrence of an extinct Vole (Microtus brecciensis) in Sardinian and Corsican pleistocene (?) deposits.

All the Alpine species mentioned except the Chamois can be easily traced to their former Asiatic home. But even it has its nearest relations in Asia. I might also refer to another Vole (Evotomys Nageri) which is practically confined to the Alps and Northern Italy, and which has probably originated there, though most of its nearest relations are either Asiatic or North American species.

But besides these Asiatic immigrants and their modified descendants we have a small truly native Alpine mammalian fauna. Sorex alpinus—the Alpine Shrew—occurs only in the Alps, the Harz Mountains, Pyrenees, and Carpathians. The genus has been found in European eocene strata,—in vastly older deposits in our own continent than elsewhere,—so that it is extremely probable that it has originated there. It may then have developed a new centre of distribution in the newly-formed Alps where both Sorex alpinus and S. minutus (pygmæus) have their home. From there they again spread—perhaps already in miocene times—to Asia and North America, where a large number of new species originated. It seems to me even probable that one of these Asiatic species of Sorex, viz. S. araneus (vulgaris), subsequently migrated towards the old home of its forefathers, since we find it more or less confined to Central and Northern Asia and Northern Europe.

Though the origin of the Alpine Hare has already been referred to and fully discussed in a previous chapter (p. [148]), the conclusions arrived at may be once more repeated. The Alpine Hare (Lepus variabilis) is of Arctic origin. It spread southward into Europe, North America, and Asia in early glacial times, and reached our continent from Spitsbergen by means of a direct land-connection with Lapland. The Scandinavian peninsula was then separated from Russia, but connected with Scotland and Ireland ([Fig. 13], p. [170]). Since England was then united to France, the Alpine Hare was able to invade western continental Europe and all the mountain ranges. Its range is very discontinuous, small colonies being scattered all over the mountainous parts of the Northern Hemisphere, while the European Hare—a closely allied species—occurs in the plain, and now occupies to some extent the former haunts of the Alpine Hare (cf. [Fig. 8], p. [137]). Might not the European Hare, as suggested, possess some advantages which enabled it to drive the other into more inaccessible parts, thus producing the peculiarity of range? The present distribution of the Alpine and the European Hare (L. Europæus) appears to me to strongly support such an assumption. It is not the cold which has driven the Alpine Hare to the Alps; and its presence there is not, as is often supposed, a "standing testimony of a former arctic climate" in Europe, but merely the necessary consequence of the weaker species being thrust into less accessible regions by a stronger rival.