Ungulates, or hoofed animals, including horses, cattle, sheep, deer, pigs, etc.
Carnivores, or flesh-eaters, including lions, cats, foxes, dogs, etc.
Rodents, or gnawing animals, among which are rats, mice, squirrels, etc.
The Primates are represented by one form only, the Barbary ape, found in Gibraltar. Bats are numerous, but are of less geographical interest than land forms. The remaining four orders are all important. The Ungulates include the largest land mammals, and their size and conspicuous nature have led to the gradual replacement of the wild forms by domesticated ones. Only a very few, such as deer, wild goats (ibex), the wild boar, the wild sheep (moufflon) of Corsica, manage to survive, and that mostly by aid of special protection. The presence of the large wild forms is incompatible with almost any form of agriculture as is often proved disastrously in Africa, hence man’s ruthless warfare upon them.
But if man has destroyed the large ungulates he has found himself unable even to reduce the numbers of the Rodents, who gain in many ways by civilisation. The destruction of their rivals, the grass-eating ungulates, increases their natural food-supply. In South America, where there were very few ungulates till the white man brought his flocks and herds, the rodents were very numerous and reached a great size. Again, the operations of agriculture give the rodents enormous artificial sources of food-supply, and the number of man’s domesticated or semi-domesticated animals makes him wage a bitter war against the small carnivores, the natural enemies of the rodents. Protected from their enemies, abundantly fed by man’s providence, it is no wonder that these small animals have multiplied greatly.
Their multiplication has been assisted by the fact that they inherit from their early days, when the struggle was keen, an enormous fertility. Many of the rodents are steppe animals, and share with steppe organisms in general the power of periodic multiplication in enormous numbers.
The steppe is a region where the rainfall is normally just enough to ensure a free growth of grass at certain seasons. Variations in rainfall, which perhaps occur in great cycles, may at one time produce a luxuriance of growth which increases the food-supply all round, and at another give rise to semi-desert conditions with a resulting enormous death-rate. The steppe organisms, then, must be very fertile because of the risks of their environment, and the Asiatic overflow is possibly determined by successions of years of abundant rainfall, which increase the number of individuals, followed by a series of years of scanty rain, which make it necessary for the overflow of population to migrate.
Among examples of European rodents we may mention the very destructive rats, mice and voles, which practically feed everywhere at man’s expense; and the hamster, an Asiatic form which reaches as far west as the Rhine, and stores large quantities of corn and other food in an elaborately made burrow. The hamster has the rodent power of rapid multiplication, and is often terribly destructive to cultivated crops. Rabbits are similarly very destructive where special precautions are not taken. Even the porcupine of southern Europe is capable of doing considerable damage. Less serious enemies of man are such forms as the following:—lemmings; marmots, of which there are two forms, an Alpine and an Asiatic, the latter extending like the other steppe animals into the plains of central Europe; beavers; squirrels; dormice; etc. These examples may be sufficient to illustrate the important points in regard to the rodents—their destructiveness, their fertility, and the fact that many were originally inhabitants of steppes and open plains, but tend, as man clears the forest-land for his own purposes, to extend their range to the cleared land, and to appropriate the new and extensive food-supply furnished by man’s industry.
While the ungulates, because of the nature of their food, must almost necessarily be rather large animals, the carnivores occur both in large and small forms. The tendency is for the large forms to be killed out with the progress of civilisation; thus the lion has wholly disappeared from Europe, wolf and bear are almost gone, but a considerable number of smaller forms still remain, such as badger, genet, wolverene, lynx, wild cat, stoat, marten, weasel, etc. The last order to be mentioned, that of the Insectivores, includes small mammals, such as moles, shrews, and hedgehogs, which feed largely on insects, but may be partially vegetarians.
As was to be expected from the climate and from the peculiar flora, the Mediterranean region possesses a richer fauna than central Europe, both as regards mammals and lower forms. Even the European portion shows considerable African influence.