Wild animals possess an endless variety of mental traits which endow them in many instances with marked individualities. Few are more strongly characterized in this respect than the marten. One of the most graceful and beautiful of our forest animals, it frequents the more inaccessible parts of the wilderness and retires shyly before the inroads of the settler’s ax. Its rich brown coat, so highly prized that the pursuit of it goes on winter after winter in all the remote forests of the North, is a source of danger threatening the existence of the species. The full-grown animal weighs five or six pounds and measures nearly three feet in length. The martens are circumpolar in distribution, and the several species occupy northern lands from England, Europe, and northern Asia to North America. Of the Old World species, the Siberian sable is best known on account of the beauty of its fine, rich fur, which renders it the most valued of all in the fur markets of the world. The North American marten is a close relative of the Siberian species, and occupies all the wooded parts of North America from the northern limit of trees southward in the forested mountains to Pennsylvania, New Mexico, and the southern part of the Sierra Nevada in California. Like other members of the weasel tribe, the marten is a fierce and merciless creature of rapine, but unlike the mink and weasel, it avoids the abodes of man and loves the remotest depths of the wilderness. Martens are endowed with an exceedingly nervous and excitable temperament, combined with all the flashing quickness of weasels. They are more restless than any other among the larger species of their notably restless tribe, and couple with this extraordinary and tireless vigor. This is admirably shown in captivity, when by the hour they dart back and forth, up and down and around their cages with almost incredible speed. In the forest they climb trees and jump from branch to branch with all the agility of a squirrel--in fact, they pursue and capture red squirrels in fair chase, and have been seen in pursuit of the big California gray squirrel (_Sciurus griseus_). On the ground they move about quickly, hunting weasel-like, under brush piles and other cover. Practically every living thing within their power falls victim to their rapacity. They eat minks, weasels, squirrels, chipmunks, wood rats, mice of many kinds, conies, snowshoe hares, ruffed and spruce grouse, and smaller birds of all kinds and their eggs, as well as frogs, fish, beetles, crickets, beechnuts, and a variety of small wild fruits. Unlike minks and weasels, they are not known to kill wantonly more than they need for food. They make nests of grass, moss, and leaves in hollow trees, under logs, among rocks, and in holes in the ground. Sometimes they have been found in possession of a red squirrel’s nest, probably after having slain and devoured the owner.