Mammals of Columbia County, Oregon

Western Oregon is a hotspot of endemic mammal diversity and the ranges of many species meet here in Columbia County. Unfortunately, several have become quite rare. Forest species struggle due to the logging of the older forest and destruction of the natural forest understory; lowland species due to the spread of development throughout flat river bottomlands.

List of all mammals recorded in Columbia County

Hoofed Mammals

columbian black-tailed deer columbia county oregon
Columbian Black-tailed Deer – Has darker tail, dark patch on the forehead, short brow tines, and antlers that fork. Found in all habitats but prefers forest/clearing edges. (photo © Brent M.)
columbian white-tailed deer columbia county oregon
Columbian White-tailed Deer– Lighter tail and forehead, long brow tines, and points come off one main branch. Prefers river bottomlands. Federally listed Endangered Species. (photo © Blu Chaney USFWS)
roosevelt elk columbia county oregon
Roosevelt Elk – Our largest land animal. Prefers mix of older forest and clearings. Requires understory vegetation to feed, thus threatened by dense tree plantations with little undergrowth. (photo © Mike Patterson)

Carnivores

mountain lion cougar puma columbia county oregon
Mountain Lion – By far our largest cat. Rarely seen as it prefers large home territories away from human activity and stays concealed even where present. (photo © Brian Wolfer ODFW)
Bobcat – About twice as large as a housecat, with bobbed tail and dark stripes/spots on lower body. Habitat generalist but secretive and rarely seen. (photo © Kala King)
Coyote – Sleeker than dogs, with slender snout and body. Larger than foxes with longer legs and a shorter tail. Habitat generalist that prefers open areas. (photo © Ken Chamberlain)
Red Fox – Mostly red but variable, with long bushy tail and white tail tip. Limited to meadows and open river bottomlands. (photo © Neal Herbert NPS)

gray fox columbia county oregon
Gray Fox – Slightly more muscular than Red Fox and much shorter than Coyote. Mostly gray body and long bushy tail with black tip. Limited to riparian woodlands. (photo © Susan Young)
Black Bear – The largest land carnivore in the region, prefers large tracks of forested land, often concentrating near berry patches or oak woodland. (photo © USFWS Northeast)

Raccoon – Unmistakable masked critter is adaptable and quite comfortable near humans, often stealing trash or dog/cat food from the proximity of homes. (photo © Jon Hakim)
Striped Skunk – Another wide-ranging small predator that adapts well to human presence, it tends to dig for insects, rodents, and eggs. (photo © B. Raeburn NPS)

River Otter – The largest local member of the weasel family. Nearly always seen within or directly next to the water, preferring larger water bodies such as rivers and lakes. (photo © Jon Hakim)
American Mink columbia county oregon
American Mink – Uniform reddish-brown to black; smaller than otter but larger than weasels. Found in wetlands and at edge of water bodies; very comfortable in water. (photo © Nathaniel Sharp)

long-tailed weasel columbia county oregon
Long-tailed Weasel – Larger than Short-tailed Weasel. Usually yellowish tint to undersides and brownish feet. Adaptable, hunting rodents and rabbits in forest and farmland. (photo © Robin Agarwal)
Short-tailed Weasel (Ermine) – Our smallest weasel, usually white underneath with white feet. Found in fields and forest edges where it hunts rodents. (photo © Colin D Jones)

Two other carnivores which may have been found in Columbia County are the American Marten and the Fisher. Both appear to be absent now, likely due to the loss of adequate forest cover.

Opossums

Virginia Opossum – Introduced from the eastern US, it tends to be more common around residences, eating grubs and worms from gardens, garbage, and mulch piles. (photo © jaco sammie)

Rabbits

Brush Rabbit – Small with generally reddish-brown coat. Found among thick brambles or brush, through which it makes extensive tunnels. (photo © hikingsandiego)
eastern cottontail columbia county oregon
Eastern Cottontail – Larger than Brush Rabbit with a grayish coat on sides. Introduced from eastern USA. Smaller than feral domesticated rabbits, which lack cotton “poof” on tail. (photo © Pedro Peloso)

Rodents

Western Gray Squirrel – Large gray squirrel with robust tail. Prefers large patches of trees away from human habitation. Now rare in the county and an ODFW Sensitive Species. (photo © James Maughn)
Eastern Gray Squirrel – Introduced species from eastern US, slightly smaller than Western Gray and with more brown. More comfortable around human habitation. (photo © Ken Schneider)

Eastern Fox Squirrel – Another large introduced squirrel from eastern US. Generally reddish-brown, sometimes with face mask. Displaces native squirrels from urban areas. (photo © Tim Guida)
Douglas Squirrel – A small tree squirrel with distinct bicolored appearance. Is somewhat dependent on mature coniferous forest, where it is often seen eating cones. (photo © ODFW)
Humboldt’s Flying Squirrel – Only emerges at night. Nests in hollows in large dead trees and glides from tree to tree. Becoming rare here due to the logging of its habitat. (photo © themooseking73)
California ground squirrel columbia county oregon
California Ground Squirrel – Our only local ground squirrel. More slender tail than tree squirrels. Lives in burrows within a variety of habitats, though avoiding dense forest. (photo © Jon Hakim)

townsend's chipmunk columbia county oregon
Townsend’s Chipmunk – Our only local chipmunk, it is larger and darker than most chipmunk species. Prefers dense forest with significant undergrowth. (photo © Jon Hakim)
North American Porcupine – This unique rodent prefers significant stands of mixed forest. It is rare in Columbia County due to destruction of its habitat. (photo © vtjohn)
North American Beaver – Our largest rodent, with a characteristic broad flat tail. Found in lakes and ponds (or streams which it transforms into ponds) within deciduous forest (photo © kingarfer)

nutria coypu columbia county oregon
Nutria (Coypu) – Smaller than beaver, with a round haired tail, long back legs, and whitish snout. Introduced from South America. Its burrows damage the banks of waterways. (photo © Diego Trillo)

Muskrat columbia county oregon
Muskrat – Smaller than a nutria, with rounded body, shorter snout, and somewhat vertically flattened tail. Found in any slow water body, where it builds lodges from vegetation. (photo © Maya)

bushy-tailed woodrat columbia county oregon
Bushy-tailed Woodrat – Furry tail makes it appear like a squirrel. Found in a variety of habitats, building “middens” in rock crevices, up in trees, or inside abandoned buildings. (photo © eheisey)
Brown Rat columbia county oregon
Brown Rat – An introduced species from Europe, much larger than any native mouse other than the Bushy-tailed Woodrat. Lives around homes and farms. (photo © Simon Tonge)

house mouse columbia county oregon
House Mouse – Generally solid brown to gray with lighter undersides. Also introduced from Europe and tends to live around dwellings. (photo © Roberto Ghiglia)

Deer Mouse – Larger eyes and ears than House Mouse, with white underbelly and haired bicolored tail. Can live virtually anywhere, will sometimes go in homes. (photo © thebirbadook)

Pacific Jumping Mouse – Course hair is dark brown on top with yellowish-brown sides. Hops rather than runs. Found in moist habitats like streamsides and wet meadows. (photo © William Leonard)
townsend's vole columbia county oregon
Townsend’s Vole – Our largest vole, 6.5-9.5″ long. Dark brown with large ears, silver belly, dark feet, dark tail only slightly lighter beneath. Found in wetlands and wet meadows. (photo © natureguy)

Long-tailed Vole – A medium-large vole, gray to grayish brown with long tail (>2.5″) that is distinctly bicolored. Large eyes and ears. Found in forest, meadow and marsh. (photo © Rick & Nora Bowers)
Grey-tailed Vole – Medium-size vole, gray to yellow-brown. Short hairy tail is dark above and light gray below. Mostly found in farmland. (photo © Dan Edge)

Creeping Vole columbia county oregon
Creeping (Oregon) Vole – Our smallest vole, 5-6″ long. Dark gray, brown, or black with a short black tail. Found in forest, grassland, and farmland. (photo © Patty Teague)
White-footed Vole – A grizzled brownish-gray vole. Longish tail dark above and white below, feet light gray or white. Partially arboreal leaf-eater, usually found near streams. (photo © Justin Brice)

western red-backed vole columbia county oregon
Western Red-backed Vole – A small vole, brown head with reddish-brown or chestnut behind and gray on the rest of the body. Prefers old-growth forest with downed logs. (photo © ODFW)

Red Tree Vole – Orangish-red to reddish-brown. Arboreal species that builds its nest in large conifers. Endangered Species candidate due to the loss of large trees, possibly gone from county. (photo © NEST)

camas pocket gopher columbia county oregon
Camas Pocket Gopher – A large gopher (10-12″), brown above and gray below with white patch on the lower jaw. Found in burns and clearcuts as well as grassy crops. (photo © Ian Silvernail)
Western (Mazama) Pocket Gopher – A small gopher, hazel to black above and buff to gray below. Found in meadows, with an isolated population in inland Columbia County. (photo © William Leonard)

northern pocket gopher columbia county oregon
Northern Pocket Gopher – Small, yellowish-brown to brownish-gray with white marks under the chin. In our area is restricted to meadows/farms in the Columbia floodplain. (photo © Bill Thomas)

mountain beaver columbia county oregon
Mountain Beaver – A unique primitive rodent reminiscent of a guinea pig. Found in moist forests, where it cuts down ferns and small seedings to drag back to its tunnels. (photo © Jordan Cochran)

Shrews and Moles

vagrant shrew oregon columbia county
Vagrant Shrew – A grayish-brown shrew with 4 or fewer friction pads on 2nd-4th toes and unique tooth structure. Frequents variety of habitats but prefers open areas with scattered trees. (photo © William Leonard)

Trowbridge's shrew columbia county oregon
Trowbridge’s shrew – Grayish-black above and below with a distinctly bicolored tail. Unique tooth structure. Digs through the soil (rather than debris) in coniferous forest. (photo © Alyssa Semerdjian)

dusky shrew oregon columbia county
Dusky shrew – Blackish-brown above and light brown below. Similar to Vagrant Shrew but with 5-6 friction pads on 2nd-4th toes and different tooth structure. Hunts in duff of coniferous forest. (photo © Carita Bergman)

Baird’s Shrew – A brown shrew, virtually identical to Dusky Shrew except for minute differences in tooth and skull structure. Found in moist coniferous forests. (photo © Lois Alexander)
Pacific Water (Marsh) Shrew – Our largest shrew at 6-7″ long, blackish with a dark tail. Found in forested wetland, spending significant time in the water. (photo © Denis Knopp)
shrew-mole columbia county oregon
Shrew-Mole – Dark gray to black, 3-4″ long, appearing midway between a shrew and a mole. Found in moist forest, especially hardwood ravines with dense leaf litter. (photo © Paul Donahue)

Coast Mole columbia county oregon
Coast Mole – A medium-sized (5-7″) mole with velvet-like dark grey to black hair. Can be found in virtually any habitat, spending all of its time underground. (photo © Jon Hakim)

townsend's mole columbia county oregon
Townsend’s Mole – A very large (over 8″) mole nearly black in color. Tends to be found in pasture and shrub habitat, avoiding forest. (photo © Peter Zika)

Bats

little brown bat myotis columbia county oregon
Little Brown Myotis – A small glossy brown bat with long ears. Found primarily in forests, especially near water, and often found roosting in attics and other buildings. (photo © Jason Headley)
long-eared myotis bat columbia county oregon
Long-eared Myotis – A dull golden-brown bat with especially long ears. A slow flier that frequents coniferous forest, where it hunts in openings. Versatile in roosting spots. (photo © Mike Cong)

yuma myotis bat columbia county oregon
Yuma Myotis – Grayish-brown to tan, similar to Little Brown Myotis but smaller and duller in color with a steeper forehead. Found in many habitats but usually hunts over water. (photo © Daniel Neal)

long-legged myotis bat columbia county oregon
Long-legged Myotis – Large myotis with long legs. Unique in that hair extends onto its wings. Calcar next to foot has a clear keel. A fast flier in coniferous forest. Sensitive Species in Oregon. (photo © Jonathan Delmer)

fringed myotis bat columbia county oregon
Fringed Myotis – Brown to olive-brown with moderately long ears. Fringe of hair on webbing near the tail. Found in woodland habitat, active over broad streams. Sensitive Species in Oregon. (photo © Gerald Carter)
Big Brown Bat columbia county oregon
California Myotis – A small bat, dark-brown in our area. Like Long-legged Myotis with keel on calcar but hair does not extend onto wings. Habitat generalist but prefers forest. Sensitive Species in Oregon. (photo © Jason Headley)

silver-haired bat columbia county oregon
Silver-haired Bat – Somewhat small, black with silver-tipped hairs. Tends to be found in older forests, where it roosts under the bark of large trees. Sensitive Species in Oregon. (photo © adamdv18)

big brown bat columbia county oregon
Big Brown Bat – Quite large, to 5″ in length and 13-14″ in wingspan. Smaller ears than myotis species. Flies slowly, hunting in variety of habitats and often roosting in homes. (photo © Ann Froschauer USFWS)
townsend's big-eared bat columbia county oregon
Townsend’s Big-eared Bat – Light brown to gray bat with very large ears. Roosts in large cavities like caves and hollow trees. Very sensitive to human disturbance. Sensitive-Critical species in Oregon. (photo © Jane Tatlock)
hoary bat Columbia county oregon
Hoary Bat – Our largest bat, reddish-brown body with silver-tipped hairs. Yellowish face with dark mask. Tends to be found in forests but hunts in open areas. Sensitive Species in Oregon. (photo © Eric Hough)

Marine Mammals

california sea lion columbia county oregon
California Sea Lion – Larger than local seals, with visible ear flaps and flippers that rotate so it can “walk” on land. Comes upstream on the Columbia River to take advantage of salmon runs. (photo © Jin Kemoole)
steller's Sea lion columbia county oregon
Steller’s Sea Lion – Larger than the California Sea Lion, lighter in color and with a broader, more “bear-like” face. Also comes up the Columbia for salmon runs. (photo © C Watts)

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