The marten is long and lithe, and its graceful activity is conspicuous. The usual color is a rich brown, shading to blackish on the feet and tail. The face is grayish with a short, dark line extending upward from the inner corner of each eye. A large orange throat and breast patch is very striking in most individuals. The fur is soft and long, the tail is long and well-furred, and serves to register various emotions. The marten is alert to sounds and this is indicated by its well-developed, broad ears.
The body is 16 to 17 inches long, and the tail, including hair at tips, 8 or 9 inches. A large male may weigh up to 2½ pounds. The female is somewhat smaller than the male.
The marten is found in the forested parts of the park along the northern and eastern boundary. In winter, I have noted a few tracks in the big spruce woods south of Wonder Lake. In Wyoming, I have found martens in rock slides beyond timber, the rock crevasses furnishing the desired protection.
Marten.
At one time the marten was thought to depend on the red squirrel for his daily fare, but recent studies indicate that ordinarily relatively few red squirrels are eaten. A food-habits study made at Castle Rocks near the northwest corner of the park showed that the martens there were living primarily on meadow voles and the red-backed mouse. Blueberries were eaten in winter as well as in summer. In Wyoming, I have found martens feeding extensively on blueberry, rhamnus, haw, and mountain ashberries by choice at a time when voles and other foods were plentiful. Like the fox and coyote, they have a strong predilection for berries. In slide rock, they manage to capture an occasional pika.
The marten breeds in July and August, but the young are not born until 9 months later. The long gestation period for such a small animal is due to the delayed attachment of the fertilized egg to the uterus. Except for the period when the female is followed by young, and during the breeding period, martens travel alone.
In Grand Teton Park, Wyoming, where I had much opportunity to observe martens, I found that, although they seldom captured a red squirrel, in their vagabond life over their home area, they did use red squirrel homes for sleeping. The marten might spend a few days resting in a squirrel’s spare nest, then move on to another squirrel domicile for a few days. The squirrels suffered only the inconvenience of an unwanted guest, and perhaps the temporary loss of a favorite bed.
Mink
Mustela vison ingens
The mink is the amphibious member of the weasel family. He lives along rivers and lakes and probably forages more in the water than on land. Fish, frogs, insects, snails, crayfish, rabbits, muskrats, and mice all appear on his bill of fare. In the country between the mouth of the Yukon and the Kuskokwim River, the mink is said to subsist largely on Alaska blackfish (Dallia pectoralis). So abundant were the mink in the area that the Eskimo were called “mink people.” The muddy waters in this watery region apparently supported enough blackfish for both the mink and the natives. This fish is said to have been the chief food of the natives. It is very tenacious of life. Kegs of live fish, packed densely, were kept for food in the dwellings. A steady slow rotary movement of the mass of fish brought each fish to the surface at intervals for a gulp of air. When a frozen blackfish is thawed, it is said to become as lively as ever.