Creeping Vole / Microtus oregoni
Distribution of the Oregon vole
|Picture from - National Museum of Natural History ©2004 Smithsonian Institution|
Area of Distribution The Oregon vole's range is from southwest British Columbia, south to west Washington, west Oregon, and northwest California. You can tell which type of vole you have by its size and distribution. The Oregon vole is smaller than the Townsend's vole, and the Oregon vole is found from the coast to the Cascade Mountains, while the Townsend's vole is found primarily on the coast and in the Coast Range.
Physical characteristics When the Oregon vole is compared to the California, Long-tailed, and the Townsend's Meadow voles, they have longer tails, larger eyes, and longer fur. It's the smallest vole in its range 5 ½ to 6 ½ inches long. The fur is short, and the color is sooty-gray to dark brown or almost black mixed with yellowish hairs, and a gray or white belly. It has small eyes and a short tail, and its ears protrude from the fur.
Reproduction It usually constructs it grass nests underground, but may place them under debris or in a hollow log. They breed from January to late November, peaking from April to May, with an average of 3-4 young.
Ecology The Oregon vole is almost entirely subterranean. Which means that they spend most of their time below ground in their burrows eating the roots of your plants. The diet of the Oregon vole is mainly green vegetation, but also includes blueberries, other berries, and underground fungi. The Oregon vole's habitat is coniferous forests, brushy and grassy areas on drier upland slopes, but burned clear-cut and grassy areas support more individuals. In Oregon clearcuts, home ranges averaged 6000 sq. ft. for males, and 9500 sq. ft. for females. If you find the highest concentration of activity by doing the Apple Sign Test first, then you can concentrate your control efforts there.
Signs of Oregon Vole Activity The Oregon vole spends most of its time in shallow burrows, which can be so close to the surface that small ridges appear as it would for a mole. It may use a mole tunnel to move around. Sometimes their tunneling and burrows are not always apparent. Look for their burrow openings as well as damage to roots, tubers and bulbs. A stressed shrub or tree may be easily moved back and forth because of the loss of their root system. If you pull it up, it may look like a sharpened pencil.
They also damage conifer seedlings less than 2" in diameter. Their damage to seedlings has distinctive characteristics. The bark is removed from ground level to about 5" up the stem and has a typically fuzzy appearance. They remove only small portions of bark because their teeth are so small. They start on one side of a seedling and progress upward, so seedlings tend to be peeled only on one side at first. Later more extensive damage may occur and they may girdle the seedling. They leave their droppings where they eat, so you may find piles of droppings at the base of damaged seedlings. Unlike other animals such as moles or pocket gophers, they don't mound dirt at their tunnel entrances, so small burrow openings that are interconnected by trails with no soil mounds are sure sign of voles.
Removing their protective cover from predators can help reduce their numbers. See Habitat Modification link.