CENTRAL OREGON WILDLIFE
SHREWS & MOLES
Preble’s Shrew (Sorex preblei)
Most Preble’s shrews live in arid or semiarid shrub-grasses that are associated with coniferous forest dominated by sagebrush. Its habitats include marshes, along streams, dry bunchgrass, and wet habitat. Grasses and sagebrush are common to most habitats. They feed on small insects and small invertebrates such as worms and centipedes. The shrew has a relatively low bite force, which suggests that it feeds on soft-bodied prey.
Little is known about the lifestyle of this shrew, but it probably has a similar lifestyle as other shrews in its ecosystem. These other shrews are often active during both the day and night. It is probable that the Preble's shrew is active all year.
Vagrant Shrew (Sorex vagrans)
The Vagrant shrew lives throughout the state except in the Columbia Basin. It usually is found in greatest numbers in moist grassy areas and more open areas with patches of shrubs and deciduous trees. They are often found close to rivers or other sources of water. This species of shrew constructs shallow cup-shaped nests, up to 3 inches across, from vegetation and animal hair. In winter, they cover the nests with a domed roof to provide shelter. This shrew feeds mainly on earthworms, spiders, insects, and other small invertebrates, but also eats some plant material. Because of their high metabolic rate, they have been reported to consume over 160 percent of their own body weight in food a day.
Vagrant shrews sometimes use echolocation to orient themselves in unfamiliar locations.
Photo: Patricia Teague
Shrew-mole (Neurotrichus gibbsii)
The shrew-mole is found at Indian Ford Campground, Deschutes County. It is most abundant in moist sod-free ravines with deep, black-silt soils with high humus content and covered with a layer of dead leaves and twigs. Dominant vegetation in these areas is bit-leaf maple, vine maple, red alder, and flowering dogwood. The shrew-mole makes two types of burrows, shallow and deep. The shallow burrows are roofed by decaying vegetation on the forest floor. This forms a complex, intersecting pathway which the shrew-mole regularly travels in search of invertebrates that have either crawled or fallen into the shallow burrows. The deep burrows, which also have a maze of pathways, are seldom over a foot deep containing the sleeping chamber. Most of the shrew-mole’s active time is spent looking for food; it may eat more than its weight in a day. This mole is often active above ground, foraging in leaf litter for earthworms, insects, snails, and slugs.
The shrew-mole is an excellent digger; it is very strong and can vertically lift almost 7 ounces—twenty times its own weight
Photo: Sarah Caufield