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
Black Bear – The largest land carnivore in the region, but surprisingly discreet. Prefers large tracks of forest, often near berry patches or oak woodland. (photo © USFWS Northeast)
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.
Virginia Opossum – Introduced from the eastern US. More common around residences, eating grubs and worms from gardens, garbage, and mulch piles. (photo © jaco sammie)
Brush Rabbit – Small with generally reddish-brown coat. Found among thick brambles or brush, through which it makes extensive tunnels. (photo © hikingsandiego)
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)
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) – Smaller than beaver, with a round haired tail and whitish snout. Introduced from South America. Its burrows damage the banks of waterways. (photo © Diego Trillo)
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 – 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 – 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 – Generally solid brown to gray with lighter undersides. No hair on tail. 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 – 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-sized vole, gray to yellow-brown. Short hairy tail is dark above and light gray below. Mostly found in farmland and yards. (photo © Dan Edge)
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)
– 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 © Western Red-backed Vole ODFW)
Red Tree Vole – Orangish-red to reddish-brown. Arboreal species that nests in conifers. ESA candidate due to the loss of large trees, may not be present in Columbia County. (photo © NEST)
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 grass 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 – 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 – 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 – 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 – 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 – Blackish-brown above and light brown below. Similar to Vagrant Shrew but with 5-6 friction pads on 2nd-4th toes and its own 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) Bats
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 – 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 – 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 – 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)
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 – 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)
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 – 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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13 thoughts on “Mammals of Columbia County, Oregon”
Nice site and good information. However, you are missing at least one species (spotted skunk), and there are no records of tree voles in Columbia County, despite quite a few surveys that were conducted in that region. So, I would say that and tell people that if they find one, please report it!
Thanks Eric! What’s the source for Spotted Skunks making it into Columbia County? I couldn’t find any records.
And Matt himself found a resin duct clump under a Doug Fir stand on the western edge of the county, with me standing next to him when he found it, and has reported it to Oregon Conservation Strategy. 🙂
We have trapped a number of mountain beaver on our property. I don’t think I’m seeing them on your list. I’d like to know more about them!
Thank you for sharing, they’re actually at the very end of the rodent section, right above shrews and moles. They are very cool creatures! Each mountain beaver builds a network of burrows in a moist hillside, you don’t see them out very much because they like to stay as close to their burrow network as possible. They cut down ferns and young shoots and other moist vegetation to eat, and will often drag some back to their burrow entrance to store.
I can to find out about the little rabbit I have seen a few times. Brush Rabbit. Thanks.
I saw a marten about 30 feet from my house about 11 AM this morning(3-17-23). This was in Scappoose near a mandatory wetlands area. It didn’t seem bothered by all the houses around it so we watched for about for about 10 mins until it moved on down the road.
That would be an incredible sighting. You’re certain it wasn’t a mink or long-tailed weasel?
Positive. I had a trap line when I was in high school and caught several mink. I’ve seen river otters on Hwy 47 but the marten looked different, especially the tail and the way an otter kind of arches its back when it is running. At first I thought I was seeing a young cougar as I’m guessing it was about 12 -15 kilos but this animal was a very dark brown. The tail looked similar to a cougar’s except it was dark brown and a bit thicker. I watched for several minutes and then snuck out the front door, walked around the corner and whistled. He turned toward me and I immediately knew what it was when I saw the chest markings. It didn’t appear excited or jittery while wandering around. He spent a few minutes sitting by the water clean out drain on the edge of the wetlands area. After discussing with the county extension office and looking at several pages of pictures I am convinced it was a pine marten. I’m not looking to brag or anything but just wanted to share the news. One of the things I thought weird was that he was walking around in a subdivision at 11AM.
After doing more research about the marten I am somewhat perplexed. The animal we saw had a tail at least 18″ long and had to weigh more than 15 lbs. Both of those figures are outside the description of a pine marten.
Hey Ron any chance it looked like this;
No. That wolverine is supposedly on an island within 10 miles of where we saw what we now believe to be fishers. Someone sent this to the PDX TV stations and the TV report at noon today(Thurs) claimed it was the state game people that took the picture. I believe that part of the report is false as a friend was sharing a cup of coffee with me on Tues afternoon and showed me this picture while we were talking about the fishers. Our thought was that if two extremely rare mammal species/varieties are seen, on the same day, in public places located less than 10 miles apart, with no apart fear of houses and people then either there was an escape from a private animal reserve or someone brought them here and purposely dumped them along the river(especially the fishers). and yes, plural means more than one was seen in the same place early Tues morning.
I’m glad you shared! If you can get a picture that would be fantastic data. I hope other people are on the lookout too.