Weasels belong to the Mustelidae family, the largest and most widely distributed group of carnivores in the world. In addition to weasels, over 50 species such as badgers, otters, minks and fishers also are included in the family. Mustelids live on all continents except Australia and Antarctica. Many family members make their homes in Oregon, including three species in the mustela genus of weasels.
Short-tailed weasels (Mustela erminea), also known as ermine, are the smallest members of the weasel genus that live in Oregon. Most of them live west of the Cascade Range although some are found in eastern Oregon. Ermine exhibit the long and lean body shape typical of weasels. They tend to spend most of their time on the ground, although they can climb trees and swim. Nocturnal as most weasels are, they hunt rabbits and rodents at night, retreating to burrows in tree roots or abandoned rodent burrows during the day.
Long-tailed weasels (Mustella fremata) live throughout the state. Those east of the Cascade Range typically have white winter coats, while those living in other parts of the state tend to keep their brown coloration year-round. These weasels, named for their bushy tails that are roughly half their body lengths, have the widest distribution of any Mustelid in the Western Hemisphere. Rather than dense forests, they prefer smaller, more open wooded areas. In Oregon they can be found near crop fields and in suburban areas where small rodents are common.
American minks (Mustela vison) are semi-aquatic weasels found throughout Oregon, particularly near rivers, lakes and marshes. Often hunted for their pelts, these sleek animals have fur ranging from dark brown to black with long guard hairs and a dense undercoat. Like other weasels, they tend to be most active at night, foraging opportunistically for prey ranging from rodents and other small mammals to fish, birds, and eggs. Although common in the state, their nocturnal and secretive behavior ensures they're seldom seen.
Other Family Members
Other Mustelid species also live in Oregon. The state's dense forests are home to martens and fishers. These animals have adapted to primarily arboreal lives to accommodate hunts for squirrels, their preferred prey. Martens live in the higher elevations of the Blue and Wallowa mountains and the Cascade Range, while fishers prefer similar habitat in lower elevations. Badgers occupy Oregon's high desert, using their fast and efficient digging skills to capture burrowing rodents such as ground squirrels and chipmunks. River otters are also found in Oregon's many rivers.
- University of Michigan Museum of Zoology: Animal Diversity Web: Mustelidae
- Oregon Department of Fish and Wildlife: Oregon's Small Mammals
- ODFW Wildlife Species: Weasels, Skunks, Badgers and Otters
- University of Michigan Museum of Zoology: Animal Diversity Web: Mustela Erminea
- University of Michigan Museum of Zoology: Animal Diversity Web: Mustela Frenata
- ARKive: American Mink Videos, Photos and Facts
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