Animals inhabiting the Arctic. The birds are chiefly sea birds, such as petrels, eider ducks, cormorants, auks, gulls, puffins, and guillemots; all are migratory. The mammals include the walrus, seals, and several varieties of whale; the polar bear, reindeer, elk, fox, wolf, ermine, and musk-ox are the principal terrestrial mammals.

Insectivorous and herbivorous habits are almost absent in arctic animals, which are either fish- or meat-eating. Many of them become snowy-white in winter; among these are birds, such as the ptarmigan, and mammals, such as the hare and lemming, which are brown in summer, and the arctic fox, which is salty-blue in summer; the polar bear is white all year round.

Molluscs, annelids, and jellyfish are common to all the northern seas, while such fish as salmon, cod, and halibut are plentiful. Insects found in the far north include bees, flies, and butterflies, but as the flora is scanty they do not occur in great abundance.