Deschutes & Ochoco National Forests
Crooked River National Grassland

Mammals

Shrews and Moles

Shrews and moles are insectivorous small mammals with long pointed noses, and five toes that are armed with claws. Shrews are the smallest of known mammals, the smallest weighing barely more than a dime. Shrews and moles have an extremely high metabolic rate and must consume at least their body weight in food daily, insects, arthropods, annelids, seeds, bulbs, and roots are consumed frequently.

The following shrews and moles are found in Central Oregon:

Baird's Shrew (Sorex bairdi)

RANGE: Endemic to Oregon, found in the coast range from the Pacific east to Portland, Multnomah Co. south of the Columbia River and south to Corvallis, Benton Co., and Reed, Lane Co. It occurs along the west slope of the Cascade range from the Columbia river south to central Lane Co.

STATUS: Not state or federally protected.

HABITAT: Open Douglas-fir forest with numerous rotting logs on the ground.

SPECIAL HABITAT REQUIREMENTS: Large rotting logs on the ground for foraging, nesting and hiding.

BREEDING:

FOOD: Small invertebrates ,including; beetles, worms, sowbugs, earthworms, centipedes, and underground fungi.

IN CENTRAL OREGON:

REFERENCES:

Broad-footed Mole (Scapanus latimanus)

RANGE: In Oregon Broad footed mole occurs in the valleys of Southwestern Oregon, specifically in Josephine Co., Jackson Co., and Klamath county.

STATUS: No state or federal protection for this specie.

HABITAT: Meadows, grasslands, and the moist riparian edges of streams and marshes.

SPECIAL HABITAT REQUIREMENTS: Loose soils with good numbers of invertebrates.

BREEDING:

FOOD: Because of the high metabolic rate of the Broad footed mole, 70% of its body mass must be consumed daily, earthworms, crickets, small insects, insect larvae, crustaceans and small vertebrates are consumed daily. Individuals occurring in coastal areas extend surface tunnels onto the beach where they consume beach hoppers.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al.; Blair,Csuti et.al.

Coast Mole (Scapanus orarius)

RANGE: Occurs from southwestern British Columbia to northwestern California, ranging east just into Idaho. Coast mole is absent in the arid areas of Oregon.

STATUS: No state or federal protection for this specie.

HABITAT: Coast mole is found in a variety of habitats including; coastal-dune pastureland, meadows, deciduous and coniferous habitats, and sagebrush.

SPECIAL HABITAT REQUIREMENTS: Light wet soil with good numbers of earthworms.

BREEDING: Breeding activity is known to occur from January to early March.

FOOD: Earthworms make up the majority of the coast moles diet, slugs, insect larvae, and adult insects are consumed as well.

IN CENTRAL OREGON: Coast mole occurs in Wasco and Crook counties.

REFERENCES: Verts and Carraway et.al., and Csuti, Blair

Fog Shrew (Sorex sonomae)

RANGE: Occurs west of the Cascade range to the coast range extending south to San Francisco Bay.

STATUS: No state or federal protection on this species.

HABITAT: Alder/salmonberry, riparian alder, and skunkcabbage marsh habitats, conifer habitats are utilized less often.

SPECIAL HABITAT REQUIREMENTS: Moist habitats, with good numbers of slugs and snails which are the primary food source of the Fog Shrew.

BREEDING: No information of the reproduction of Fog Shrew is available.

FOOD: Slugs and snails are the primary food source of the Fog shrew, centipedes, insectc larvae, and fungi contribute to the diet of Fog shrew.

IN CENTRAL OREGON: Does not occur in central Oregon.

REFERENCES: Verts and Carraway et.al.

Merriam Shrew (Sorex merriami)

RANGE: North central Washington south through Oregon east of the Cascade range into eastern California, to Arizona, New Mexico, north central Colorado western Nebraska and North Dakota, and the eastern half of Montana.

STATUS: No federal or state status for Merriam shrew.

HABITAT: Arid environments such as sagebrush steppe and Juniper woodlands are utilized most often. Mountian mahogany habitats have been used in Wyoming.

SPECIAL HABITAT REQUIREMENTS:

BREEDING: Evidence of breeding has been noted during the months of March through October.

FOOD: Spiders, caterpillars, cave crickets,and insect eggs contribute to a substantial portion of Merriam shrews diet.

IN CENTRAL OREGON: Merriam shrew has been found in Wasco county Oregon

REFERENCES: Verts and Carraway et.al., Csuti,Blair et.al.

Pacific Marsh Shrew (Sorex bendirei)

RANGE: In Oregon, Pacific marsh shrew occurs in the North Cascade in Clackamas Hood river and Multnomah counties, west into Clatsop, Columbia,and Washington counties, and southeasterly from Newport, Lincon Co., through Benton, Lane, Linn, Jackson, and Klamath counties. The specie does not occur in the interior valleys of western Oregon.

STATUS: Not state or federally protected.

HABITAT: Pacific Marsh Shrew can be found in Alder riparian areas, skunk cabbage marshes, deep dark red cedar swamps in which they live upon floating mats of yellow cress,and muddy marshy areas of forests and forest edges. Pacific marsh shrews have been known to utilize all succesional stages of forest, ranging from early seral to mature forests.

SPECIAL HABITAT REQUIREMENTS: Riparian or aquatic environments that provide soft bodied prey.

BREEDING:

FOOD: Pacific marsh shrew feeds on aquatic insects, insect larvae, slugs and snails, earthworms, centipedes, spiders, and will even swim, diving to catch fish.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al.

Preble's Shrew (Sorex preblei)

RANGE: In Oregon Preble's shrew occurs in Deschutes, Grant, Klamath, Lake, Harney, and Wallowa counties.

STATUS: No state protection, federally Preble's shrew is a specie of concern.

HABITAT: In Oregon Preble's shrew occupies sagebrush-bunchgrass habitats, big sagebrush-bitterbrush habitat,and Quaking Aspen stands.

SPECIAL HABITAT REQUIREMENTS: Throughout the United States Preble's shrew has been found in many types of habitat, this suggests Preble's shrews requirements may be more specific than that of dominant vegetation types or soil moisture content.

BREEDING: Little is known regarding the nesting habits of Preeble's shrew as it is hard to capture, and shares habitat with three other species of shrew.

FOOD: Based on the relatively low bite force of Preeble's shrew, skull and tooth morphology, inferences have been made to suggest the diet may consist of a soft diet of invertebrates

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.el., Csuti,Blair et.al.

Shrew-mole (Neurotrichus gibbsii)

RANGE: Occurs west of the Cascade and Sierra Nevada ranges from the Frasier river area of British Columbia south to the Monterey area of California.

STATUS: No state or federal protection for this species.

HABITAT: Most abundant in deep humus free soils in deep ravines. Dominant vegetation in these sites include big leafed maple, vine maple, red alder, flowering dogwood, various deciduous shrubs and brambles, sword fern, mosses and skunk cabbage. Shrew moles occur less frequently in shallow soils, such as those encountered in burned over areas, headland prarie, dry woods or areas with a stony or rocky substrate.

SPECIAL HABITAT REQUIREMENTS: Deep non-compacted soil as Shrew moles construct extensive runway networks about 40mm wide and 20mm deep in soft soil beneath the duff layer.

BREEDING:

FOOD: Shrew moles are unique in that it has the size and forefeet of a shrew, and the large head and dental structure of a mole, and it's unique ability to climb low bushes to forage for insects, earthworms, insect larva, and adult insects are consumed.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al.

Trowbridge's Shrew (Sorex trowbridgii)

RANGE: Occurs in southern British Columbia, south through Oregon and Washington, from the coast and as far east as the Cascade range. In California Trowbridge's shrew is limited to the coastal ranges and Sierra Nevada

STATUS: Not state or federally protected

HABITAT: All successional stages of forest are utilized by Trowbridge's shrew however, late successional forests typically have the highest population of Trowbridge's shrew.

SPECIAL HABITAT REQUIREMENTS: Deep, non compacted organic layer for nesting purposes, associated with coniferous forests.

BREEDING: Burrows are dug within the layer of organic debris on the forest floor

FOOD:Trowbridge's shrew is a food generalist, the foods ingested are indicative of the wide variety of habitats occupied by this shrew, foods ingested include; centipedes, spiders, internal organs of invertebrates, slugs, snails, Douglas-fir, white pine and mushrooms.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al. , Csuti,Blair et.al.

Vagrant Shrew (Sorex vagrans)

RANGE: Vagrant Shrew occurs from southern British Columbia and Southern Alberta through Oregon,Washington, and coastal and montane regions of California to Monterey bay and Yosemite National park. In Oregon the vagrant shrew occurs everywhere except in the Columbia basin.

STATUS: Not state or federally protected.

HABITAT: A generalist in terms of habitat, vagrant shrew occurs in highest densities in moist grassy areas, and in open patches within deciduous forests, specifically, red alder-common swordfern habitats with a deep organic layer.

SPECIAL HABITAT REQUIREMENTS: Vagrant shrew require deep, non compacted organic layers of soil above the mineral soil for excavating, and hiding from predators.

BREEDING: Nests are usually constructed beneath a piece of bark or other shelter, moss, grass, and other insulating materials are used to construct the nest.

FOOD: A food generalist, vagrant shrew is known to consume, insect larvae, slugs, snails, earthworms, spiders, caterpillars, moths, flies, fungi and a variety of herbs and shrubs. Vagrant shrew must consume more than their body weight each day.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al

Water (Northern) shrew (Sorex palustris)

RANGE: Occurs from Alaska and Central Canada, across the northern United States and south into mountainous areas to the Mexican border. Absent from the plains states, Texas and the southeastern United States.

STATUS: No state or federal protection for this species.

HABITAT: Almost always found close to water, undercut banks, exposed tree roots, and boulder strewn streamsides vegetated by willow provide prime habitat for water shrews.

SPECIAL HABITAT REQUIREMENTS: Water and is closely associated with the beaver.

BREEDING:

FOOD:Earthworms, slugs, snails, mice, fish, salamanders, stonefly nymphs, caddis flies, mayflies crickets spiders and leeches have been documented as most frequently consumed.

IN CENTRAL OREGON:

REFERENCES: Verts and Carraway et.al.