Arctic foxes feed largely on sea-birds and lemmings, laying up hidden stores of the last-named rodents for winter use.
Foxes and lemmings are met with, but whereas animals are few, birds are very numerous; a variety of ducks, waders, &c., frequent the marshes and lakes.
The lemmings are very numerous, and in certain years undertake migrations to the mainland and back.
Reindeer, followed by wolves, come also every year to the islands; the polar fox and polar bear, both feeding on the lemmings, are numerous.
The circumpolar lemmings of the genera Lemmus and Dicrostonyx are noticed in the article Lemming.
These sudden appearances of vast bodies of lemmings, and their singular habit of persistently pursuing the same onward course of migration, have given rise to various speculations, from the ancient belief of the Norwegian peasants, shared by Olaus Magnus, that they fall down from the clouds, to the hypothesis that they are acting in obedience to an instinct inherited from ancient times, and still seeking the congenial home in the submerged Atlantis, to which their ancestors of the Miocene period were wont to resort when driven from their ordinary dwelling-places by crowding or scarcity of food.
When any combination of circumstances has occasioned an increase of the numbers of the lemmings in their ordinary dwelling-places, impelled by the restless or migratory instinct possessed in a less developed degree by so many of their congeners, a movement takes place at the edge of the elevated plateau, and a migration towards the lower-lying land begins.
For habits of lemmings, see R.
It breeds abundantly in some seasons on the fells of Lapland, its appearance depending chiefly on the presence of lemmings (Lemmus norvegicus), on which it mainly preys.
Of Phanerogams, only the Dryas octopetala covers small areas of the debris, interspersed with isolated Cochlearia, &c., and, where a layer of thinner clay has been deposited in sheltered places, the surface is covered with saxifrages, &c.; and a carpet of mosses allows the arctic willow (Salix polaris) to develop. Where a thin sheet of humus, fertilized by lemmings, has accumulated, a few flowering plants appear, but even so their brilliant flowers spring direct from the soil, concealing the developed leaflets, while their horizontally spread roots grow out of proportion; only the Salix lanata rises to 7 or 8 in., sending out roots I in.
The interior of Novaya Zemlya shows hardly a trace of animal life, save here and there a vagrant bird, a few lemmings, an ice-fox, a brown or white bear, and at times immigrant reindeer.
In common with lemmings and other representatives of the Microtinae, voles are, however, broadly distinguished from typical rats and mice by the structure of their three pairs of molar teeth.