Oregon Department of Fish and Wildlife
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last updated: 02/20/2014
 
Oregon Species

Oregon Wildlife Species

Mammal Species of Oregon - Rats and Mice

Opossum | Shrews, Moles, and Shrew-moles | Bats | Pikas, Rabbits and Hares | Mountain beaver | Squirrels, Chipmunks, and Marmots | Pocket Gophers | Pocket Mice, Kangaroo Rats and Kangaroo Mouse | Beavers | Rats, Mice, Voles, Muskrats | Porcupines | Coyotes, Wolves and Foxes | Bears | Seals and Sea Lions | Ringtails and Raccoons | Weasels, Badgers, Otters and Skunks | Cats | Hoofed Mammals | Whales, Dolphins and Porpoises
Order Rodentia
Pocket Mice, Kangaroo Rats and Kangaroo Mouse - Family Heteromyd

Little Pocket Mouse Perognathus longimembris

The Little Pocket Mouse is one of the smallest rodents in North America and certainly the smallest in Oregon. The dorsal pelage is pinkish buff to ocherous buff with overlying blackish hairs; the venter is buff. The tail is bicolored.

In Oregon, this mouse occurs in Harney and Malheur counties.

They exhibit their greatest activity from spring through autumn and spend a large portion of their lives in burrows below the surface of the ground. In winter, they remain underground continuously, relying on stored seeds for energy. When active on the surface, a large portion of their time is spent searching beneath shrubs for seeds. Items are identified as seeds by touch and placed in their pouches by use of the forefeet.

Great Basin Pocket Mouse Perognathus parvus

The Great Basin Pocket Mouse is the larger member of the genus in Oregon. The dorsal pelage of this mouse is pinkish buff or ocherous buff overlain with black hairs; the venter is white to buffy. A lateral line, usually somewhat olive colored, separates the dorsal and ventral pelages. The tail is distinctly bicolored.

In Oregon it occurs thought east of the Cascade Range, except it does not occur in the Wallowa and Blue mountains.

The Great Basin Pocket Mouse constructs burrows below the surface that contain granaries for storage of food, a nest cavity, and several entrances. They spend much of their lives in their burrows; even during the active season they usually are above ground only late in the evening or at night.

Dark Kangaroo Mouse Microdipodops megacephalus

The pelage of this mouse is grayish or brownish dorsally, the venter hairs are white with lead-colored bases. The tail is light colored.

In Oregon, it occurs within the area circumscribed by a line connecting Denio Nevada; Fort Rock, Lake County; Powell Butte, Crook County; Malheur National Wildlife headquarters, Harney County; and Burns Junction, Malheur County.

On a daily basis, activity begins with an intense burst during the first to hours after sunset, and declines to almost nil 6 hours after sunset, then, especially in summer, increases again before sunrise. The Dark Kangaroo Mouse constructs elaborate nests with cached seeds in its burrow system and sleeps on its back.

California Kangaroo Rat Dipodomys californicus

The California Kangaroo Rat is the largest kangaroo rat in Oregon, but is only of moderate size within the genus. It has a moderately broad face, relatively large ears, and awl-shaped lower incisors. The tail is 150 percent of the length of the head and body. It is the darkest-colored kangaroo rat in Oregon. The pelage of the dorsum is composed of hairs with dark-gray bases, a narrow dark-buff band and black terminus. The venter, feet; upper lip; and base, sides, and tip of tail are white' there is a white spot above each eye and behind each ear. A white stripe across each hind leg isolates a patch of dorsum-colored fur. A black moustache, eyelids and tail stripes and white and black splotched ears produce a striking attire for this handsome rodent.

In Oregon it occurs only in the southern portions of Jackson, Klamath and Lake County. It does not hibernate and may be active even when snow covers the ground or when its raining. Activity is nocturnal, commencing shortly after dark. It constructs burrows as daytime retreats, often beneath boulders.

Chisel-toothed Kangaroo Rat Dipodomys microps

The Chisel-toothed Kangaroo Rat is an intermediate-sized kangaroo rat with a narrow face, small ears, and flat-faced, nearly square-edged lower incisors shaped like miniature chisels. Among kangaroo rats, the cheek pouches in relation to the size of the head are exceptionally large. The pelage on the dorsum is composed of hairs with medium-gray bases, a buffy band, and a tiny blackish tip, overall a dirty-sand color. The venter, upper lip, feet, and base and sides of the tail are white and there is a white spot above each eye and behind each ear. A black moustache, eyelids, ears and tail stripes complete the pelage of this strikingly marked small mammal.

In Oregon it occurs in Lake, Harney, and Malheur counties south of a line connecting Summer Lake, Malheur Lake, and Watson in the three counties, respectively. It is associated with shrub-dominated habitats.

It is nocturnal, activity begins at twilight until a time of about the same light intensity in the morning. The Chisel-toothed Kangaroo Rat constructs multientrance burrows with Greasewood the dominant shrub at mound sites.

Ord's Kangaroo Rat
Ord's Kangaroo Rat
-Wikipedia-

Ord's Kangaroo Rat Dipodomys ordii

The Ord's Kangaroo Rat is a medium sized kangaroo rat with awl-shaped lower incisors. It is the lightest-colored kangaroo rat in Oregon; overall the dorsum is a rich buff with gray overtones. The venter, upper lip, feet and side of the tail are white; there is a white spot above each eye and behind each ear; and a white stripe crosses each thigh. The moustache, eyelids, and ears are blackish.

In Oregon, it occurs east of a line connecting The Dalles, Hood River County; Sisters, Deschutes County; and Lakeview, Lake County except in the Ochoco, Blue, and Wallowa mountains.

Although occasionally seen abroad during daylight hours, Ord's Kangaroo Rat is active mostly at night; however, nighttime activity is affected by moonlight, temperature, and inclement weather. Burrows commonly are constructed beneath desert shrubs, and excavated earth thrown up often buries the lower branches. Burrows usually are kept plugged by residents to prevent escape of moisture and entrance of predators.

Sources: Land Mammals of Oregon by B.J. Verts and Leslie N. Carraway


Oregon Department of Fish and Wildlife
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