Fig. 60. Wolverine (Gulo luscus), male, trapped by Reuben R. Lamb, March 22, 1941, three miles south of Riverside, Washington; reported to weigh 40 pounds; dried pelt 3 × 4 feet. (Reuben R. Lamb photo.)
Fig. 61. Distribution of the wolverine, Gulo luscus luteus, in Washington.
The wolverine is adapted to boreal conditions and is most abundant in the arctic. In the Cascades it occurs only at or near timber-line. Except the wolf and the possibly extinct grizzly bear, the wolverine is the rarest carnivore in Washington. Probably it has been rare since the retreat of the continental glaciers, for suitable habitat for wolverines is not abundant and each animal requires a large area over which to range. An unusual record, possibly of a wandering animal, is given by [Scheffer] (1941: 37). This is of an adult male taken in the Okanogan Valley 3 miles south of Riverside, Okanogan County, on March 22, 1941.
Lutra canadensis (Schreber)
River otter
Description.—The otter has the long body of many mustelids, but is specialized for aquatic life. Males are slightly larger than females. Large adults measure more than 3-1/2 feet in length, of which the tail comprises 18 inches. The largest adults may weigh as much as 25 pounds. The body is elongate but rather plump. The forelimbs are small and laterally placed. The hind legs are the heavier, and are situated posteriorly. The feet are large and webbed for swimming. The tail is long, thick at the base and gradually tapering to a narrow tip. The head is small and rounded. The ears are tiny and the eyes are of moderate size. The upper lips are large, somewhat spaniel-like, and support a mustache of stiff vibrissae. The fur is short, dense and soft. The tail is sleek with short, posteriorly-directed fur, and is not bushy. The fur is rich, dark chocolate brown in color, slightly paler on the animal's underparts than on its upper parts.
Otters range over Eurasia, North America and South America. Those occurring in North America north of Mexico are thought to belong to a single species, canadensis. Several species from tropical America may eventually be shown to also be races of canadensis.